Physical assessment device with coordinated led drive circuit for image capture

ABSTRACT

A physical assessment device includes an instrument head, an optical assembly and an adapter interface member. The instrument head includes an illumination assembly including at least one LED and a drive circuit for powering the at least one LED with a pulse width modulation (PWM) current to achieve a variable brightness of the at least one LED. The optical assembly includes a plurality of optical components disposed along an optical axis. The adapter interface member enables an image capture device to be attached to the instrument head and aligned with the optical axis. The image capture device is configured to capture images of medical targets when illuminated by the at least one LED. The drive circuit is coordinated with the image capture device to ensure that the medical targets are at least partially illuminated during the capturing of the images notwithstanding the variable brightness of the at least one LED.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/258,226, filed Apr. 19, 2021, and is a continuation in part ofU.S. patent application Ser. No. 17/483,347, filed Sep. 23, 2021, whichis a continuation of U.S. patent application Ser. No. 16/248,482 (nowU.S. Pat. No. 11,147,441), issued Oct. 19, 2021, which claims priorityto U.S. Provisional Patent Application No. 62/617,929, filed Jan. 16,2018, each of which are incorporated herein by reference in theirentirety for all purposes.

TECHNICAL FIELD

This application is generally directed to the field of diagnosticmedicine and more specifically to an improved physical assessmentdevice, (e.g., an otoscope or ophthalmoscope), which is configured forperforming diagnostic patient examinations.

BACKGROUND

Physical assessment devices are well known in the field of diagnosticmedicine for examining patients as part of wellness visits and/orroutine examinations. These devices include, among others, otoscopes fordiagnosing conditions of the ear, ophthalmoscopes for diagnosingconditions associated with the eye of a patient, and dermatoscopes forexamining the skin of a patient. Each of these physical assessmentdevices typically includes an instrument head that is releasablyattached to the upper end of an instrument handle, the latter containinga set of batteries, enabling the devices to be compact and capable ofbeing handled with one hand. The instrument head can retain optics thatenable an image of a medical target (e.g., ear, eye) to be viewed by acaregiver through an eyepiece, or alternatively the image of the medicaltarget can be transmitted to an electronic imager associated with thephysical assessment device. Suitable illumination of the medical targetof interest is provided by a resident light source, such as anincandescent lamp. Incandescent lamps may be dimmed using knowntechniques, so that the medical target will be illuminated with theappropriate contrast for visibility. The electronic imager may be usedto capture an image of the medical target for later use by the caregiveror other medical professional.

There is a general need in the field of diagnostic medicine to improvephysical assessment devices, such those described above.

BRIEF DESCRIPTION

According to one aspect, there is provided a physical assessment device.The physical assessment device includes an instrument head, an opticalassembly and an adapter interface member. The instrument head has adistal end, an opposing proximal end and an interior. The instrumenthead includes an illumination assembly including at least one LED and adrive circuit for powering the at least one LED with a pulse widthmodulation (PWM) current to achieve a variable brightness of the atleast one LED. The optical assembly is disposed within the instrumenthead and includes a plurality of optical components disposed along anoptical axis. The adapter interface member is disposed at the proximalend of the instrument head, and enables an image capture device to beattached to the instrument head and aligned with the optical axis. Theimage capture device is configured to capture images of medical targetswhen illuminated by the at least one LED with the variable brightness.The drive circuit is coordinated with the image capture device to ensurethat the medical targets are at least partially illuminated during thecapturing of the images notwithstanding the variable brightness of theat least one LED being achieved using the PWM current.

In one aspect, the drive circuit is coordinated with the image capturedevice to ensure that the medical targets are at least partiallyilluminated during the capturing of the images by selecting a frequencyof a duty cycle of the drive circuit to include at least two on-cyclesof the PWM current to overlap with an image scanning period of the imagecapture device.

In another aspect, the drive circuit is coordinated with the imagecapture device to ensure that the medical targets are at least partiallyilluminated during the capturing of the images by selecting the drivecircuit to output a substantially triangle wave current with a minimumcurrent value greater than zero.

One advantage realized by the herein described physical assessmentdevice is that a imaging device, such as that included in a smart phone,can be mechanically and optically coupled to a device, such as anotoscope or ophthalmoscope, which is typically only configured foroptical viewing by a caregiver. When so coupled, a medical target may beilluminated with an appropriate brightness of an LED light of theassessment device and an image may be captured by the smart device, suchthat the image is free of defects and artifacts (or has a reduced amountof defects and artifacts) that would otherwise impede use of the imageby a caregiver or other medical professional.

These and other features and advantages will be apparent from thefollowing Detailed Description, which should be read in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a side elevational view of a physical assessment devicemade in accordance with an embodiment;

FIG. 1(b) is a front perspective view of the physical assessment deviceof FIG. 1(a);

FIG. 2(a) is a side elevational view of the instrument head of thephysical assessment device of FIGS. 1(a) and 1(b);

FIG. 2(b) is a side view taken in section, of the instrument head ofFIGS. 1(a)-2(a);

FIG. 2(c) is a rear facing view of the instrument head of FIGS.1(a)-2(b);

FIG. 2(d) is a rear perspective view of the instrument head of FIGS.1(a)-2(c);

FIG. 2(e) is a another rear perspective view of the instrument head ofFIGS. 1(a)-2(d);

FIG. 2(f) is a side perspective view of the instrument head of FIGS.1(a)-2(e);

FIG. 2(g) is another side perspective view of the instrument head ofFIGS. 1(a)-2(f);

FIG. 2(h) is a bottom plan view of the instrument head of FIGS.1(a)-2(g);

FIG. 2(i) is a top plan view of the instrument head of FIGS. 1(a)-2(h);

FIG. 2(j) is a left side elevation view of the instrument head of FIGS.1(a)-2(i);

FIG. 2(k) is a right side elevation view of the instrument head of FIGS.1(a)-2(j);

FIG. 3 is an exploded assembly view of the instrument head shown in FIG.1(a)-FIG. 2(k);

FIG. 4 is an exploded view of a lens tube fitted within the instrumenthead of FIGS. 1(a)-FIG. 3;

FIG. 5(a) is a side perspective view of an instrument head in accordancewith an alternative embodiment;

FIG. 5(b) is a side view, taken in section, of the instrument head ofFIG. 5(a);

FIGS. 6 and 7 are exploded assembly views of a smart device adapter madein accordance with an exemplary embodiment;

FIG. 8(a) is a front facing view of the smart device adapter of FIGS. 6and 7;

FIG. 8(b) is a sectioned view of the adapter taken through line 8-8 ofFIG. 8(a);

FIG. 9(a) is a rear facing view of the smart device adapter of FIGS.8(a) and 8(b);

FIG. 9(b) is a side sectioned view of the smart device adapter takenthrough section lines 9-9 of FIG. 9(a);

FIGS. 10(a)-10(e) are views depicting a sequential assembly flow of thesmart device adapter of FIGS. 6-9(b);

FIG. 11(a) is a partially broken away view of a smart device adapterhaving an attached device engagement member;

FIG. 11(b) is a partial rear perspective view of the smart deviceadapter of FIGS. 6-11(a);

FIG. 11(c) is a left side elevation view of the smart device adapter ofFIGS. 6-11(b);

FIG. 11(d) is a right side elevation view of the smart device adapter ofFIGS. 6-11(c);

FIG. 11(e) is a front view of the smart device adapter of FIGS. 6-11(d);

FIG. 11(f) is a rear view of the smart device adapter of FIGS. 6-11(e);

FIG. 11(g) is a top plan view of the smart device adapter of FIGS.6-11(f);

FIG. 11(h) is a bottom plan view of the smart device adapter of FIGS.6-11(g);

FIG. 11(i) is a front perspective view of the smart device adapter ofFIGS. 6-11(h);

FIG. 11(j) is a bottom perspective view of the smart device adapter ofFIGS. 6-11(i);

FIG. 11(k) is a rear perspective view of the smart device adapter ofFIGS. 6-11(j);

FIG. 11(l) is another bottom view of the smart device adapter of FIGS.6-11(k);

FIG. 12(a) is a left side view of a device engagement member inaccordance with an embodiment;

FIG. 12(b) is a front view of the device engagement member of FIG.12(a);

FIG. 12(c) is a rear facing view of the device engagement member ofFIGS. 12(a) and 12(b);

FIG. 12(d) is a top plan view of the device engagement member of FIGS.12(a)-12(c);

FIG. 12(e) is a bottom view of the device engagement member of FIGS.12(a)-12(d);

FIG. 12(f) is a front perspective view of the device engagement memberof FIGS. 12(a)-12(e);

FIG. 12(g) is a rear perspective view of the device engagement member ofFIGS. 12(a)-12(f);

FIG. 12(h) is another rear perspective view of the device engagementmember of FIGS. 12(a)-12(g);

FIG. 13(a) is a partial side view, taken in section, of the smart deviceadapter of FIGS. 6-11(l) and device engagement member of FIGS.12(a)-12(h), as assembled to the physical assessment device of FIGS.1(a)-5;

FIG. 13(b) is the side sectioned view of the instrument head of FIGS.2(b)-2(k), smart device adapter of FIGS. 6-11(l) and device engagementmember of FIGS. 12(a)-12(h), further depicting a ray trace of theoptical system or assembly including a distal entrance pupil produced bythe optical system;

FIG. 14 is a partially assembled rear perspective view of a knownphysical assessment device having a smart device adapter made inaccordance with another embodiment;

FIG. 15 is an exploded assembly view of the smart device adapter of FIG.14;

FIG. 16 is a front perspective view of the physical assessment device ofFIG. 14 as assembled with the smart device adapter of FIG. 15 prior to asmart device being releasably attached;

FIG. 17 depicts a prior art physical assessment device (on the left)with the physical assessment device of FIGS. 1-5(b) as shown in side byside relation;

FIG. 18 is a side perspective view of the prior art physical assessmentdevice having an attached smart device adapter, which is made inaccordance with another embodiment;

FIG. 19 is another perspective view of the prior art physical assessmentdevice and smart device adapter of FIG. 18;

FIG. 20 is a front perspective view of the smart device adapter of FIGS.18 and 19;

FIG. 21 is a perspective view of a physical assessment device made inaccordance with another embodiment;

FIG. 22 is a perspective view of a physical assessment device made inaccordance with yet another embodiment;

FIG. 23 is a rear perspective view of the instrument head of thephysical assessment device of FIG. 21;

FIG. 24(a) is a perspective view of the instrument head of the physicalassessment device of FIG. 22;

FIG. 24(b) is a rear perspective view of the instrument head of FIG.24(a), including an attached smart device;

FIGS. 25(a), 25(c) and 25(d) are partial assembly views and FIG. 25(b)is an assembled view of the instrument head of FIGS. 21 and 23;

FIGS. 26(a) and 26(b) are partially assembled and assembled views of theinstrument head of FIGS. 22 and 24(a);

FIG. 27 is a sectioned elevational view of the instrument head of FIGS.21, 23 and 25(a)-25(d);

FIG. 28 is a sectioned elevational view of the instrument head of FIGS.22, 24(a) and 26(a) and 26(b);

FIG. 29 is a perspective view of an instrument head for a physicalassessment device made in accordance with another embodiment;

FIG. 30 is a perspective view of an instrument head for a physicalassessment device in accordance with yet another embodiment;

FIG. 31 is a perspective of an intermediate assembly strap used in theinstrument heads of FIGS. 29 and 30;

FIG. 32 is a sectioned partial view of the bottom of an instrument headdepicting the securement of the intermediate assembly strap of FIG. 31to an instrument head;

FIG. 33 is a sectioned partial view of an instrument head of a physicalassessment device in accordance with an embodiment;

FIG. 34 is an enlarged sectioned view of a portion of the instrumenthead of FIG. 33, including an integrated component of the illuminationassembly used for centering a contained LED and collimating lightemitted from the LED;

FIG. 35 is a partially cutaway top perspective view depicting theintegrated component of FIG. 34 within the instrument head relative tothe retained LED;

FIG. 36 is a top perspective view of the integrated component of FIGS.34 and 35;

FIG. 37 is an side elevational view in section of the physicalassessment device of FIG. 21;

FIG. 38 is an enlarged elevational view of the top of an instrumenthandle of a physical assessment device in accordance with an embodiment;

FIG. 39 is a bottom perspective view of an instrument head configured toengage the instrument handle of FIG. 38;

FIG. 40 is an enlarged portion of the instrument head of FIG. 39;

FIG. 41 is a partial sectioned view of the physical assessment device ofFIG. 37, depicting the engagement between the instrument head andinstrument handle;

FIG. 42 is an enlarged view of a portion of FIG. 41;

FIG. 43 is an enlarged portion of the instrument handle of FIG. 38;

FIG. 44 is an elevational view of an instrument handle for a physicalassessment device in accordance with an embodiment;

FIG. 45 is a sectioned partial view of the top of the instrument handleof FIGS. 37 and 38;

FIG. 46 is a partial sectioned view of the instrument handle of FIGS. 37and 45, depicting aspects of a rheostat assembly in accordance with anembodiment;

FIG. 47 is a perspective view of a detent ring member of the rheostatassembly of FIG. 46;

FIG. 48 is a perspective view of an instrument handle made in accordancewith another embodiment;

FIG. 49 is a partial sectioned view of the instrument handle of FIG. 48,depicting a USB charging port;

FIG. 50 is a sectioned view of the instrument handle of FIGS. 48 and 49,illustrating battery charging contacts;

FIG. 51 is the sectioned view of FIG. 50, illustrating the engagement ofthe instrument handle with a charging base or cradle;

FIG. 52 is a perspective view of a charging base or cradle having a pairof physical assessment devices attached thereto;

FIG. 53 is a sectioned view of an instrument handle including a featurefor detecting overheating of a contained battery;

FIG. 54(a) presents an optical layout of the physical assessment deviceof FIG. 13(b);

FIG. 54(b) depicts a comparison of layouts between an optical assemblyof a known physical assessment device with other versions in accordancewith various embodiments of the invention;

FIG. 55 illustrates the advantageous effect of the inventive opticalassemblies of FIGS. 54(a) and 54(b) relative to an attached accessory ofthe physical assessment device, as compared to an existing opticalassembly;

FIG. 56 is a layout of an alternative optical system, which is definedhaving glass components in lieu of plastically molded components;

FIGS. 57(a) and 57(b) are side perspective views of a physicalassessment device made in accordance with another embodiment;

FIG. 58 is an exploded view of the instrument head of the physicalassessment device of FIGS. 57(a) and 57(b);

FIG. 59(a) is a side elevation view in section of the instrument head ofFIG. 58, further depicting a ray trace of a contained optical assembly;

FIG. 59(b) is the side elevation view in section of the instrument headof FIG. 59(a), further depicting a ray trace of a contained illuminationassembly;

FIG. 60(a)-60(d) are various views of an adjustable mirror mountassembly of the instrument head of FIGS. 58-59(b);

FIG. 61 is a side elevational view of a physical assessment device madein accordance with another embodiment;

FIG. 62 is a partial front perspective view of a physical assessmentdevice having an attached smart device;

FIG. 63 is a front perspective view of an instrument head of thephysical assessment device of FIG. 62, including an attached eye cup;

FIGS. 64(a) and 64(b) are side elevation view, one in section of the eyecup of FIG. 63 having a disposable ring member in accordance with anembodiment;

FIG. 65 is a sectioned view of the instrument head of a physicalassessment device in accordance with another embodiment;

FIG. 66 is an overall schematic view of the optical and illuminationassemblies of the physical assessment device of FIG. 65;

FIG. 67 is a ray trace diagram of the illumination assembly of thephysical assessment device of FIGS. 65 and 66;

FIG. 68 is a ray trace diagram of the optical assembly of the physicalassessment device of FIGS. 65-67;

FIG. 69 is a front view of the distal end of the instrument head of FIG.65, depicting a pair of spaced fixation target illuminators;

FIG. 70 is an enlarged sectioned view of the lower portion of theinstrument head of FIG. 65;

FIG. 71(a) is an enlarged sectioned view of a portion of FIG. 65;

FIG. 71(b) is a perspective view of the mirror support member of FIG.71(a);

FIGS. 72(a) and 72(b) are partial perspective views, partially insection, of a portion of the optical assembly, including the rotatablediopter wheel of the instrument head of FIGS. 65-67;

FIG. 73 depicts a comparative layout of a pair of optical assemblies fora physical assessment device;

FIG. 74 illustrates physical assessment devices having the opticalassemblies illustrated in FIG. 73;

FIG. 75 illustrates various ray traces of an illumination assemblyaccording to an embodiment as compared to an existing illuminationassembly;

FIGS. 76(a) and 76(b) depict instrument heads typically used forophthalmic examinations in which the instrument heads can be configuredfor otological examinations in accordance with exemplary embodiments;

FIG. 77 is a block diagram of a circuit for controlling LED lighting inan instrument head in accordance with an embodiment;

FIG. 78 is a flowchart depicting a method for controlling LED lightingin an instrument head in accordance with an embodiment;

FIG. 79 is a circuit diagram of the controller of FIG. 77;

FIG. 80 is a circuit diagram of the power conversion circuit of FIG. 77;

FIG. 81 is a circuit diagram of the FET full-wave bridge circuit of FIG.77;

FIG. 82 illustrates an electrical circuit diagram of a field-effecttransistor (FET) rectifier/bridge in accordance with another exemplaryembodiment;

FIGS. 83(a) and 83(b) illustrates a diagram of an LED drive circuit inaccordance with another exemplary embodiment;

FIG. 84 illustrates an electrical circuit in accordance with anotherembodiment enabling an instrument handle to be charged using a chargingbase or via USB;

FIGS. 85(a) and 85(b) are diagrams of circuits that will drive both anLED and halogen based lamp from a single varying power source andmaintain loop stability so that there is no risk of blinking LEDs;

FIG. 86 is a schematic diagram of a voltage boost circuit made inaccordance with an embodiment;

FIG. 87 depicts PWM dimming of an LED light;

FIGS. 88A-88B depict an images of medical targets with artifacts, whenusing PWM dimming;

FIG. 89 depicts one example of a drive circuit for capturing images ofmedical targets free of artifacts in accordance with an embodiment;

FIG. 90 depicts another example of a drive circuit for capturing imagesof medical targets free of artifacts in accordance with an embodiment;

FIG. 91 depicts a substantially triangle wave current produced by thedrive circuit of FIGS. 90; and

FIG. 92 depicts an example of capturing an image of medical target freeof artifacts in accordance with an embodiment.

DETAILED DESCRIPTION

The following relates to various embodiments of physical assessmentdevices that are typically used for examining a patient, and morespecifically otoscopes typically used for examining the ears of apatient and ophthalmoscopes typically used for examining the eyes of apatient. It will be readily apparent to the reader from the descriptionthat follows that a number of the herein described features can beincorporated into physical assessment devices other than those beingdescribed. In addition, a number of the inventive features described arenot confined to any specific embodiment and are equally applicable toother described embodiments/devices. In addition, a number of terms areused throughout the following description for purposes of providing asuitable frame of reference in regard to the accompanying drawings.These terms, which include “first”, “second”, “upper”, “lower”, “left”,“right”, “above”, “below”, “distal”, “proximal”, “interior”, “exterior”,“internal” and “external”, among others, are not intended to limit anyof the described inventive aspects, except where so specifically andconspicuously indicated. In addition and for purposes of clarity, likereference numerals are used throughout the discussion of each of thevarious embodiments.

In addition, the drawings provided are intended to show salient featuresof the herein described physical assessment devices. The drawings,however, are not intended to provide scalar relationships between any ofthe various depicted components unless specified to the contrary.

Otoscope

A first physical assessment device (otoscope) is described. FIGS. 1(a)and 1(b) depict a side view and a front perspective view of the physicalassessment device, respectively, which according to this embodiment isan otoscope 100. The otoscope 100 is designed primarily for performingdiagnostic examinations of the ear of a patient, although the hereindescribed physical assessment device 100 can also be used for examiningother anatomical cavities (i.e., the nose, throat) of a patient. Theotoscope 100 is defined by an instrument head 104 that is releasablyattached to the upper end of an instrument handle or handle portion 108.The instrument handle 108 is sized and shaped to permit the otoscope 100to be handheld and is further configured to retain at least one battery(not shown in these views) for powering a light source (not shown)contained in the instrument head 104. The contained light source isenergized by an on-off button 118 disposed on the exterior of the handleportion 108, wherein the illumination output of the contained lightsource can be controlled using a rheostat 117, the latter including atwistable portion formed on the handle portion 108. The containedbattery can preferably be recharged via a charging port 119, which isprovided in the bottom end of the handle portion 108.

As shown in FIG. 2(a), the instrument head 104 according to thisembodiment is defined by a body or housing having a distal or patientend 112 and an opposing proximal or caregiver end 116. A hollow speculumtip element 120 is releasably attached to the distal end 112 of theinstrument head 104, the speculum tip element 120 being designed andshaped to fit a predetermined distance into the ear canal while theproximal end 116 of the instrument head 104 includes an adapterinterface member 180.

The interior of the instrument head 104 is essentially hollow and sizedand configured to retain a plurality of components. With reference toFIGS. 2(a)-2(k) and 3 and according to this exemplary embodiment, theinstrument head 104 includes a pair of mated housing sections;specifically a front housing section 130 and a rear housing section 134.Each housing section 130, 134 is a shell-like member made from astructural material, such as a moldable plastic. Each of the housingsections 130, 134 are mated to one another according to this embodimentusing fasteners 136, FIG. 3, to define an interior cavity.Alternatively, the housing sections 130, 134 can also be secured bywelding, such as ultrasonic welding or other suitable means. Asdiscussed in greater detail in a later portion of this description, thelower ends 131, 135 of each of the housing sections 130, 134 areretained at the bottom of the instrument head 104 using a securing ring280. According to this embodiment, a peripheral bumper 137 is disposedbetween the front and rear housing sections 130, 134. An innerformer 138disposed within the interior of the front housing section 130 includes aconical distal portion 139, as well as a lower portion 141. Theinnerformer 138 is essentially hollow and defines an interior cavity ofthe instrument head 104 to enable insufflation via a port connector (notshown) extending outwardly to a corresponding access opening 114, FIG.1(b), formed in the front housing section 130.

With reference to FIGS. 2(b)-4, the herein described otoscope 100retains an optical assembly that includes a hollow lens tube 152containing a plurality of optical components is supported within theinterior of the instrument head 104 and more specifically within theinnerformer 138. The lens tube 152 is defined by opposing distal andproximal ends 154, 156, respectively. An objective lens 160 is fittedwithin the distal end 154 of the lens tube 152 adjacent an opticalwindow 161 that covers the distal end 154 of the lens tube 152. Acylindrical hollow spacer 163 is provided proximally of the objectivelens 160 along with a relay lens 166, each of the spacer 163 and relaylens 166 being disposed within an intermediate axial portion 155 of thelens tube 152. The diameter of the lens tube 152 further widens at itsproximal end 156, which retains an imaging lens 169 disposed in relationto a field stop 170 with a coiled spring 172 being disposedtherebetween. A threaded retaining cap 175 at the proximal end 156 ofthe lens tube 152 maintains pressure against the imaging lens 169. Inaddition, a field stop 164 is disposed within the lens tube 152 betweenthe window 161 and objective lens 160 to reduce light scatter and anaperture plate 167 is disposed within the lens tube 152 proximal to therelay lens 166.

As shown in FIGS. 2(b), 3 and 4, the proximal threaded portion 157 ofthe hollow lens tube 152 engages a set of corresponding internal threadsformed on a distal portion of the adapter interface member 180. Theadapter interface member 180 is a substantially cylindrical sectionaccording to this embodiment having its distal portion 182 extendinginto the proximal end 116 of the instrument head 104 and furtherincluding an outwardly extending proximal portion 188. A recess 184defined between the distal and proximal portions 182, 188 of the adapterinterface member 180 is sized and configured to receive a smart deviceadapter 300, partially shown in FIG. 5. The recess 184, is substantiallyannular with the inclusion of a series of machined flats 186, FIG. 2(a)and FIGS. 2(d)-2(k). According to this embodiment, four (4) flats 186are provided, although the specific number can be suitably varied.Further details relating to the smart device adapter 300 are describedin greater detail in a subsequent section of this application.

When assembled, the distal end 154 of the hollow lens tube 152 ispositioned at the distal end 112 of the instrument head 104 with theopposing proximal end 156 of the lens tube 152 extending from an openingformed in the innerformer 138. The adapter interface member 180 isthreadingly engaged with the proximal end 156 of the hollow lens tube152 and extends outwardly from an opening formed in the rear housingsection 134 of the instrument head 104.

A series of circumferentially spaced axial openings 183 are providedwithin the distal portion 182 of the adapter interface member 180. Eachaxial opening 183, which extends into the defined recess 184, receives acoiled compression spring 185 as well as a ball 187, the latterextending partially into the recess 184 to provide positive engagementwith a smart device adapter 300, when the latter is attached. Anintermediate plate 190 is positioned onto the exterior of the proximalend 156 of the lens tube 152 distally relative to the threaded portionof the lens tube 152 and in contact with a sealing member 142. Accordingto this embodiment, the adapter interface member 180 is further definedby an interior that includes an optical window 189 secured within theoutwardly extending proximal portion 188. A brow rest or cap 194 coversthe extending proximal portion 188 of the adapter interface member 180.

The sealing member 142 is made from an elastomeric material and disposedat the proximal end of the innerformer 138 on a formed annular shoulder.When assembled, the sealing member 142 is further engaged against theintermediate plate 190 and the adapter interface member 180 to provideadequate sealing within the innerformer 138 to enable insufflation of apatient.

With further reference to FIGS. 2(b) and 3, the distal end 154 of thehollow lens tube 152 extends through the distal insertion portion 140such that the optical window 161 and adjacent objective lens 160 aredisposed at the distal end 154 of the distal insertion portion 140. Aspreviously discussed, a speculum tip element 120 is releasably attachedto the distal end 112 of the instrument head 104. According to thisembodiment, the speculum tip element 120 is a hollow member made from alightweight molded plastic material defined by a truncatedfrusto-conical shape having a distal tip opening 124 and an opposingproximal tip opening 128. The exterior surface of the speculum tipelement 120 at its proximal end includes at least one engagement featurethat enables the speculum tip element 120 to be releasably attached tothe distal end 112 of the instrument head 104. According to thisspecific version, a total of three (3) engagement features are provided,each engagement feature including a ramped surface having a series ofclosely spaced engagement teeth.

The speculum tip element 120 is disposed in overlaying relation onto adistal insertion portion 140, the latter being defined by asubstantially conical surface that is disposed in overlaying relationonto the conical distal portion 139 of the innerformer 138. According tothis exemplary amendment, the innerformer 138 can include at least oneexterior feature shaped and configured for engaging and retaining thedistal insertion portion 140. The speculum tip element 120 is releasablysecured to a distal ring member 146, the latter being disposed withinthe distal end of the front housing section 130 with the distalinsertion portion 140 extending distally outward of the distal ringmember 146.

The distal ring member 146, which is disposed relative to the fronthousing section 130 includes a number of engagement features that areconfigured to permit releasable attachment of the speculum tip element120. More specifically, the distal ring member 146 includes a pluralityof ramped surfaces formed at circumferentially spaced locations, eachramped surface being shaped and configured to engage the exteriorengagement features of the speculum tip member 120. According to thisembodiment, the distal ring member 146 is configured to receive one of aplurality of speculum tip elements 120, including those havinginstrumentation, each tip element 120 having exterior engagementfeatures that engage with the ramped surfaces of the distal ring member146.

The speculum tip element 120 is mounted onto the distal insertionportion 140 with the exterior engagement features of the speculum tipelement 120 being engaged by the ramped surfaces provided on the distalring member 146. The speculum tip element 120 is secured and released bymeans of an appropriate twisting motion. As noted and when attached, thespeculum tip element 120 is designed to be fitted up to a predetermineddistance into the ear canal of the patient.

The foregoing components combine to define the optical assembly for theherein described otoscope 100. As described in later portions of thisapplication, a smart device adapter can be attached to the adapterinterface member 180 to enable a smart device (e.g., a smart phone) tobe attached to the instrument head 104 and enable images of the earcanal and more specifically the tympanic membrane to be captured.

An alternative version of an otoscopic instrument head 104A is shown inFIGS. 5(a) and 5(b). Similar parts are labeled with the same referencenumerals for the sake of clarity. This instrument head 104A according tothis embodiment includes the front housing portion 130, a rear housingportion 134A and an innerformer 138, as well as a distal insertionmember 140, distal ring member 146 and sealing member 142. However, thisspecific instrument version does not include a lens tube or an adapterinterface member. In lieu of these components, the instrument head 104Aincludes an eyepiece window 196 that is provided at the proximal end 116within a cover portion 198 disposed within the rear housing portion134A. The eyepiece window 196 may or may not be configured to provideoptical power (magnification) for enhanced viewing of the medicaltarget.

With reference to FIGS. 2(b), 3 and 5(b), the lower portion of each ofthe herein described instrument heads 104, 104A retains an illuminationassembly. According to this version, the light source of theillumination assembly is an LED 244, which is disposed upon the uppersurface of a printed circuit board 240. The circuit board 240 iselectrically coupled to a downwardly depending electrical contact 220,the latter being retained within an insulator member 224 biased by aspring 254, which is disposed within a lens retainer 248 provided abovethe circuit board 240, along with a condensing lens 250. The oppositeend of the electrical contact 220 extends from an opening formed in theinsulator member 224 and a handle stud base member 270. The securingring 280 is secured over the lower end of the handle stud base member270. The handle stud base member 270 includes an intermediate recessedportion 273 that is sized to retain the lower ends 131, 135 of the frontand rear housing sections 130, 134, 134A of the instrument head 104,which is engaged by the securing ring 280. According to at least oneversion, the securing ring 280 can include a locking element, such as,for example, a pin (not shown) that is insertable through a transverseopening 281 formed in the securing ring 280.

The circuit board 240 is retained upon an upper shoulder of the handlestud base member 270 according to this embodiment. The condensing lens250 is integrally molded as a domed section into the lens retainer 248that is disposed above the LED 244 and circuit board 240. According tothis version, the lens retainer 248 is made from a moldable plastic. Oneend of the biasing spring 254 acts upon a surface of the lens retainer248, allowing the LED 244 and condensing lens 250 to be aligned andsuitably positioned relative to the lower portion 141 of the innerformer138 and more specifically a sleeve 144 that retains the polished end ofa set of optical fibers (not shown). The optical fibers are advancedupwardly within the innerformer 138 and extend as a ringlet (not shown)that is provided in an annular spacing between the distal insertionportion 140 and the conical distal section 139 of the innerformer 138 inorder to emit light toward the target of interest.

In operation, the contained LED 244 is engaged electrically via thecontact 220, as biased by the retained spring 254. Upon energization ofthe LED 244 by the on/off switch 118, FIG. 1(a) provided on the handleportion 108, FIG. 1(a), illumination from the LED 244 is directedthrough the condensing lens 250 with the collimated light being directedto the polished proximal end of the optical fibers (not shown) at alower end of the innerformer 138. As noted, the optical fibers (notshown) are directed through the innerformer 138 with the distal ends ofthe optical fibers being arranged in a ring-like configuration at thedistal end opening of the distal insertion portion 140 and about theperiphery of the hollow lens tube 152.

Smart Device Adapter

As shown in FIGS. 6-13(b), a smart device adapter 300 in accordance withan exemplary embodiment is described. The smart device adapter 300 isreleasably attachable to the proximal end 116, FIG. 1(a), of a suitablyconfigured physical assessment device, such as the previously describedotoscope 100, FIG. 1(a). The smart device adapter 300 according to thisexemplary embodiment is defined by an housing or body 304 having a pairof housing sections, namely a front housing section 308 and a rearhousing section 312, which when assembled combine to create an interiorthat is suitably sized and shaped to retain a plurality of components.Each of the components of the smart device adapter 300 according to thisembodiment are manufactured from a moldable plastic, although othersuitable materials can be used.

The front housing section 308 of the smart device adapter 300 is definedby a lower portion 320, which includes a semicircular slot 322 providedat one end. The semicircular slot 322 extends entirely through thethickness of the front housing section 308 with the exception of adevice engagement section 328, which is most clearly depicted in FIG.8(a), as well as FIGS. 11(e), 11(i) and 11(j).

The device engagement portion 328 is defined by a pair of deviceengagement surfaces 330, 332, each of which extend inwardly relative tothe formed slot 322 and adjacent a front facing surface 309 of the fronthousing section 308. These engagement surfaces 330, 332 are orthogonalto one another and have a defined thickness.

The front facing surface 309 of the front housing section 308 furtherincludes a recess 335, FIG. 6, adjacent the defined semicircular slot322 on one side of the slot 322 opposite one of the engagement surfaces330. The recess 335 is sized and configured to receive a slider member350, which is secured by a slider retainer 356. According to thisembodiment, the slider member 350 is defined by an upper plate 352having an edge surface 354, as well as a lower portion 353. The sliderretainer 356 is attached to the lower portion 353 of the slider member350 using at least one fastener 358, as well as engagement between adownwardly extending tab of the lower portion 353 of the slider member350 and a corresponding slot formed in an upper surface of the sliderretainer 356. When positioned within the recess 335, the edge surface354 of the slider member 350 is positioned at the same plane as the twodevice engagement surfaces 330, 332, thereby forming a third deviceengagement surface. As shown in FIG. 8(b), a compression spring 346 isprovided within a lateral cavity formed in the lower portion 353 of theslider member 350 that engages a spring pin provided on the fronthousing portion 308, laterally biasing the slider member 350 and morespecifically the edge surface 354 inwardly relative to the formed slot322. To facilitate movement, the underside of the upper plate 352 of theslider member 350 includes a set of rails 359 that are configured toslide within corresponding tracks 355 formed in the front housingportion 308.

With reference to FIGS. 6, 7, 11(b) and 11(f), the rear housing section312 of the smart device adapter 300 includes respective interior andexterior surfaces 313, 314. A slot 316 is formed at a lower end of therear housing section 312. The slot 316 is further defined by an interiorridge 324. A peripheral border 326 formed on the interior surface 313extends around the formed slot 316, as well as the entire perimeter ofthe rear housing section 312. As discussed herein, the portion of theperipheral border 326 about the slot 316 and the interior ridge 324 aresized and configured to support a detent cover 370, as well as a deviceengagement member 360. The peripheral border 326 includes a semicircularsection at the lower end of the rear housing section 312 thatcorresponds to the semicircular slot 322 formed in the front housingsection 308 of the herein described adapter 300. A through opening 327is also formed at the lower end of the rear housing section 308 as partof a protruding portion 340.

According to this embodiment, the detent cover 370 is an elongate memberhaving a front facing surface 371 and opposing rear facing surface 372that is sized and configured to be fitted within the formed slot 316 ofthe rear housing portion 312. A molded projecting portion 373 isprovided on the front facing surface 371 of the detent cover 370 that issized to accommodate a detent member 384, as well as a detent spring394. The molded projecting portion 373 is circular in configurationaccording to this exemplary embodiment and includes a pair ofdiametrically spaced slots 375 that are sized to engage ears 389 formedon the detent member 384 to insure a predetermined placement within theprojecting portion 373. It will be readily apparent that the moldedprojecting portion 373 can assume other suitable configurations. Theprojecting portion 373 is further defined by a through opening extendingentirely through the thickness of the detent cover 370, the openingenabling access to a projecting detent 391.

Adjacent the molded projecting portion 373 on the front facing surface371 of the detent cover 370 is a formed recess 376 that is sized andconfigured to receive a strip of insulating material 395. According tothis embodiment, the strip of insulating material 395 is made from anopen-celled foam material such as poron, although other similarmaterials can be utilized.

The device engagement member 360 is attachable to the rear housingsection 312 of the smart device adapter 300 and more specifically isattachable to the formed slot 316. According to this embodiment, thedevice engagement member 360 is elongate and defined by opposing planarfront and rear facing sides 361, 362, respectively. The rear facing sideor surface 362 of the device engagement member 360 receives an adhesivestrip 363, which can be fitted thereto. According to one version andwith reference to FIGS. 6, 7 and 12(a)-12(h), the rear facing surface362 of the device engagement member 360 is defined by a recess 366 sizedto accommodate the adhesive strip 363 and position it in a predeterminedlocation and orientation. According to another version, the adhesivestrip can be removed and relocated anywhere on the rear facing side 362.The front facing side 361 of the device engagement member 360 includes agroove 367 which is formed transversely relative to the major dimensionof the member 360 and adjacent one end.

An exemplary assembly flow is provided in FIGS. 10(a)-10(e). First andwith reference to FIG. 10(a), the slider member 350 is attached to thefront housing section 308 and fitted within the formed recess 335 withthe lower portion 353 of the slider member 350 extending through anaccess slot provided in the front facing surface 309. The compressionspring 346 is engaged within the lateral slot formed in the lowerportion 353 of the slider member 350 wherein one end of the compressionspring 346 is engaged with a spring pin (shown in FIG. 10(a)). As shownin FIG. 10(b), the slider retainer 384 is then attached to the slidermember 350 through the access slot by engaging the tab of the lowerportion 353 with the corresponding slot formed in the upper surface ofthe slider retainer 356 and inserting the fastener 358 to secure theslider retainer 356 and the slider member 350 within the recess 335 ofthe front housing portion 308.

As shown in FIG. 10(c), the strip of insulating material 395 is added tothe recess 376 formed in the rear housing section 312 and the detentmember 384 and detent spring 394 is placed within the projectingenclosure 373 of the detent cover 370, aligning the ears 389 of thedetent member 384 with the corresponding spaced slots 375 formed on theprojecting enclosure 373. Once the foregoing components are in place,the detent cover 370 is placed onto the interior side of the rearhousing section 312 and more specifically, the slot 316 with a borderingedge of the detent cover 370 being placed on the peripheral border 326.

As shown in FIG. 10(d), the front housing section 308 having theassembled slider member 350 and slider retainer 356 is then aligned withand attached to the rear housing section 312 having the assembled detentcover 370, detent member 384 and detent spring 394, as well as the stripof insulating material 395.

Finally and as shown in FIG. 10(e), the rear housing section 312 and thefront housing section 308 are secured using a series of threadedfasteners 317 through a series of mounting holes 315 provided in each ofthe rear housing portion 312 and front housing portion 308 of the smartdevice adapter 300. When assembled, the detent cover 370 is sandwichedwithin the interior of the smart device adapter 300 along with thedetent member 384, the detent spring 394 and the strip of insulatingmaterial 395, and with the slider member 350 also attached as shown.

The device engagement member 360 can then be slidingly attached to theslot 316. With reference to FIGS. 9(a), 9(b), 11(a), 11(b) and 11(k),the detent member 384 is retained in the interior of the adapter 300within the detent cover 370. The detent member 384 according to thisembodiment includes a projecting detent 391 that is sized and shaped toengage the transverse groove 367 formed on the front surface 361 of thedevice engagement member 360 when the device engagement member 360 isattached by sliding the device engagement member 360 within the open endof the formed slot 316.

As shown in FIGS. 9(a), 9(b) and 11(a) and as the device engagementmember 360 is engaged within the slot 316 of the rear housing section312, the bias of the detent spring 394 enables the detent member 384 tobe moved slightly forward relative to the transverse groove 367 formedin the device engagement member 360 to provide greater retention whenthe device engagement member 360 is attached to the adapter 300. Thestrip or pad of insulating material 395 eliminates rattle and provides adefined drag when a user slides the device engagement member 360 in thedefined slot 316. The device engagement member 360 is slid anappropriate distance within the slot 316 until the front surface of thedevice engagement member 360 engages the spring loaded detent member384. Preferably, there is a slight mismatch created between theprojecting detent 391 and the transverse groove 367 formed in the deviceengagement member 360 that biases the device engagement member 360forward. Additional views of the front and rear interfacing portions ofthe smart device adapter 300 illustrating each of the foregoing featuresare depicted in FIGS. 11(a)-11(l).

In operation, the device engagement member 360 can first be attached toa smart device using a fixture (not shown) to a facing surface of asmart device. The device engagement member 360 is preferably located onthe smart device (e.g., smart phone) in a position that enables theoptical axis of the smart device to be aligned with the optical axis ofthe physical assessment device when the smart device is attached. Thethrough opening 327 of the rear housing section 312 is aligned with theoptical axis of the smart device when the device engagement member 360is attached to the smart device. When attached, the protruding portion340 formed on the rear housing portion 312 of the adapter 300 minimizesthe intrusion of ambient (room) light into the system.

With reference to FIG. 13(a), the smart device adapter 300 is attachableto the proximal end 116 of the physical assessment device 100 byaligning the device engagement portion 328 of the adapter 300 with therecess 184 of the adapter interface member 180. The three engagementsurfaces 330, 332 and 354 have a thickness that enables a fit within therecess 184 of the adapter interface member 180. Moreover, theconfiguration of the three (3) device engagement surfaces 330, 332 and354 of the smart device adapter 300, including their length and relativespacing enables releasable attachment of the smart device adapter 300relative to the recess 184 of the adapter interface member 180, and morespecifically the machined flats 186. The slot 322 of the front housingsection 308 of the adapter 300 is sufficiently wide so as to accommodatethe proximal section 188 of the adapter interface member 180, includingthe brow rest 194.

As noted, the engagement surface 354 is biased due to the spring loadedslider member providing consistent peripheral contact of the engagementsurfaces 330, 332 and 354 with the machined flats 186. In addition, theaxial openings of the adapter interface member and more specifically thespring loaded balls 187 of the adapter interface member 180 against theintermediate plate 190, further bias the attached smart device adapter300 in the direction of the optical axis of the physical assessmentdevice 100 and provide a stable mounted platform for purposes ofconducting an examination.

For purposes of positioning, the smart device adapter 300 (and attachedsmart device (not shown) can be placed in one of four (4) differentpositions, each position clocked about 90 degrees about the optical axisof the physical assessment device 100. According to this embodiment, thesmart device adapter 300 is removed from the physical assessment device100 and rotated before reengaging the slots of the adapter 300 with themachined flats 186 of the adapter interface member 180. This adjustmentcan be made either with or without a smart phone being attached to thesmart device adapter 300. It will be understood, for example, that thenumber of machined flats can be suitably varied in order to provide asuitable number of mounting positions.

According to another embodiment, the herein described adapter can befitted to a physical assessment device, such as an otoscope orophthalmoscope, without prior optical alignment using a calibrationdevice. Instead of attaching the device engagement member 360 adhesivelyor otherwise to the smart device following calibration, the deviceengagement member 360 is initially attached to the smart device adapter300 by sliding the device engagement member 360 into the slot 316provided on the rear housing portion of the adapter 300 until there isan audible or other indication that the device engagement member 360 hasbeen placed at a predetermined position. In at least one version, anaudible click or other indication, such as a detent is provided to theuser. The adhesive layer 363 of the device engagement member 360 is thenremoved to enable the device engagement member 360 to be attached to afacing surface of the smart device, wherein visual alignment by the useraligns the through opening 327 in the adapter 300 with the optical axisof the attached smart device. The two components can then be assembledby pressing the adhesive surface 363 of the device engagement member 360against the front facing side of the smart device. To remove the smartdevice from the adapter 300, the smart device can be pulled from thedevice engagement member 360. This technique permits a varied number ofdifferently sized smart devices to be releasable fitted to a commonsmart device adapter 300.

As shown by the ray trace depicted in FIG. 13(b) for the physicalassessment device 100 including instrument head 104 and attached smartdevice adapter 300, the optical assembly of the herein describedotoscope 100 creates a virtual distal entrance pupil 125 within theattached speculum tip element 120, FIG. 2(a). The position of the formedentrance pupil according to this embodiment is well distal of theoptical window and objective lens. The entrance pupil is positioned suchthat the attached speculum tip element 120 is not “seen”; that is, therays of light reflected from the medical target pass sufficiently withinthe tip opening of the speculum tip element 120, FIG. 2(a), while stillenabling a large field of view, permitting the entire tympanic membraneto be viewed all at once. As shown, the light reflected from the medicaltarget is directed along a defined optical axis to the optics of anattached smart device, not shown. The advantageous effect of theentrance pupil is further illustrated in FIGS. 54(a) and 55.

With reference to FIGS. 14-16, a variation of the smart device adapter400 is described for use on another physical assessment device 450.Similar parts are labeled with the same reference numerals for the sakeof clarity. According to this embodiment, the physical assessment device450 is a Pan Optic™ Ophthalmoscope sold commercially by Welch Allyn,Inc. of Skaneateles Falls, N.Y. The ophthalmoscope 450 is defined by aninstrument head 454 that can be releasably attached to a handle portion(not shown). The instrument head 454 includes a distal (patient) end 456and an opposing proximal (caregiver) end 459. An optical system (notshown) within the instrument head 454 is configured to enableexaminations of the eye of a patient, along with a containedillumination system (not shown) that includes at least one light sourceto illuminate the eye being examined.

According to this embodiment, aspects of the smart device adapter 400are structurally and functionally similar to the version previouslydescribed in FIGS. 6-13(a), including a pair of housing portions 308,312 that retain a detent cover 370 as well as a detent member 384, thelatter being biased by a contained detent spring 394. The rear housingportion 312 includes a slot 316 that is configured to receive the detentcover 370, as well as a device engagement member 360 that is slidablyengaged with the slot 316 formed on the adapter 400 and including atransverse groove 367 that engages the detent member 384. The housingportions 308, 312 are secured to one another using a set of fasteners317, The adapter 400 further includes a through opening 327 that isaligned with the optical axis of the physical assessment device 450 whenthe adapter 400 (and smart device 480) are attached, as shown in FIG.16.

The smart device adapter 400 according to this embodiment furtherincludes a flexible arm 420 having a distal end 424 that includes aring-shaped portion 428. The ring-shaped portion 428 is sized to enableit to be disposed over the downwardly extending portion 458 of theinstrument head 454. The proximal end 429 of the flexible arm 420 can bereleasably attached to the front housing section 308 of the smart deviceadapter 400. According to this version, the front housing section 308includes an opening 433 that is sized to receive the proximal end 429 ofthe flexible arm 420.

With reference to FIGS. 17-20, a smart device adapter made in accordancewith another exemplary embodiment is herein described. First andreferring to FIG. 17, a known physical assessment device 500 and theotoscope 100, FIG. 1(a), are shown in side by side relation. Aspreviously discussed, the otoscope 100 includes an adapter interfacemember 180 at its proximal end 116 that enables a smart device adapter300, FIG. 6, to be releasably attached. The known assessment device 500,which is a Macroview™ otoscope, commercially sold by Welch Allyn, Inc.of Skaneateles Falls, N.Y., can also be configured with an adapter toenable a smart device to be attached. The known device is defined by aninstrument head 554 that includes a distal (patient) end 556 and anopposing (caregiver) end 559, wherein the instrument head 554 isattached to the upper end of a handle portion 558. A speculum tipelement 560 is attached to the distal end 556 of the instrument head554. An optical and an illumination assembly (not shown) are containedwithin the instrument 550, including an eyepiece 563 provided at theproximal end 558 and a focusing wheel 562 intermediately provided on theexterior of the instrument head 554 that enables relative movement of atleast one contained optical element (not shown).

With reference to FIGS. 18-20, a smart device adapter 500 according tothis embodiment includes a support or base plate 504 having an upperportion 508 and an opposing lower portion 512. The support plate 508 canbe made from a durable molded plastic, although other structuralmaterials can be suitably utilized. The upper portion 508 includes athrough opening 516, as well as a hollow cylindrically shaped projection520 that is aligned with the through opening 516. The hollow projection520 extends distally from the upper portion 508 and is defined by acavity that is sized and configured to be fitted over the proximal end558 and more specifically the eyepiece 563 of the known physicalassessment device 550. A flexible engagement portion 522 formed at thelower portion 512 of the base plate 504 is defined by a C-shapedengagement end 524. This engagement end 524 is sized and configured toreleasably engage the cylindrical handle portion 558 of the knownphysical assessment device 500. Though the known physical assessmentdevice 550 is an otoscope, it will be readily apparent to those in thefield that other handheld medical diagnostic devices can be similarlyconfigured for attachment.

With further reference to FIGS. 18-20 and in terms of attachment, theprojecting cylindrical portion 520 is first fitted onto the proximal end558 of the physical assessment device 550. This fit still enables thecaregiver to access the focusing mechanism 562 of the physicalassessment device 550. The smart device adapter 500 is then rotateduntil the open end of the C-shaped engagement feature 524 is alignedwith the handle portion 558, permitting the C-shaped engagement feature524 to be clamped onto the handle 558. The C-shaped engagement portion556 is angled relative to the base plate 504 to account for the angledconfiguration of the instrument head 554 of the otoscope 550.

A smart device such as a smart phone (not shown) can be attached to theproximal side of the support plate 504 in a manner similar to thosepreviously described. Advantageously, the herein described adapter 500can be attached to a physical assessment device in a matter of seconds,thereby converting the physical assessment device from an optical to adigital physical assessment device without requiring any modification tothe device. Once attached, the smart device permits users to use thephysical assessment device 550 to take pictures and video and thenseamlessly transfer the images or video to a digital medical record orother digital storage medium used in an office or hospital.

Variations—Otoscope

An otoscope 1100 made in accordance with another exemplary embodiment isdepicted in FIGS. 21 and 23. According to this embodiment, theinstrument head 1104 of the otoscope 1100 is defined by a distal end1112, an opposing proximal end 1116 and a downwardly extending portion1120 attached to the handle 1108, the latter being shown only in FIG.21. A disposable hollow speculum tip element 1124 is releasably attachedto the distal end 1112 of the instrument head 1104 and more specificallyto a tip retaining member 1170, while an optical window 1128 is providedat the proximal end 1116. In use, the speculum tip 1124 is shaped andconfigured to be inserted a predetermined distance into the ear of thepatient and the optical window 1128 enables viewing of a medical targetof interest (e.g., the tympanic membrane) through the open distalopening 1125 of the speculum tip 1124.

With reference to FIGS. 22 and 24(a), an alternative instrument head1204 of an otoscope 1200 is similarly defined by a distal end 1212, anopposing proximal end 1216 and a downwardly extending portion 1220. Adisposable speculum tip element 1124 is releasably attached to thedistal end 1212 of the instrument head 1204 and more specifically a tipretaining member 1170. As shown in FIG. 24(b), a rear mounting member1224 (also referred to throughout as an adapter interface member)extending from the proximal end 1216 is configured to receive a smartdevice 1230, such as a smart phone, using an interface member 1240 thataligns the electronic imager of the smart device 1230 with an opticalaxis of the instrument 1200 to enable digital imaging of the target ofinterest (e.g. the tympanic membrane) via the display 1234 of theattached smart device 1230.

Assembly of the instrument head 1104 is shown in FIGS. 25(a)-25(d). Theinstrument head 1104 according to this embodiment includes a pair ofhousing sections 1134, 1138 (one housing section 1134 being shown asexploded in FIG. 25(a)) that are mated to one another about aninnerformer 1140, the latter component creating an interior chamber forthe instrument head 1104. An interface stud 1150 extends downwardly fromthe innerformer 1140 into the downwardly extending portion 1120 of theinstrument head 1104 to enable connection to the instrument handle 1108,FIG. 21. A conically-shaped distal insertion portion 1160 is provided atthe distal end 1112 of the instrument head 1104 onto which the speculumtip 1124 is placed in overlaying relation and releasably secured to thetip retaining member 1170. A proximal housing member 1180 is secured tothe rear end of the innerformer 1140. The proximal housing member 1180includes a mounting flange 1184 having a pair of spaced slots 1186 thatpermits the transverse attachment of the optical window 1128. Betweenthe mounted proximal housing member 1180 and the rear of the innerformer1140 is a groove 1187 that permits the inclusion of a sealing member(not shown). A retaining ring 1190 threadingly attached to the interfacestud 1150 secures the housing sections 1134, 1138 together and a cover1142 attached to the top of the instrument head 1104 covers the matingedges of the housing sections 1134, 1138.

With reference to FIGS. 26(a)-26(b), the assembly of the instrument head1204 similarly incorporates the housing portions 1134, 1138 that aremated about the innerformer 1150, the latter component forming aninterior compartment of the instrument head 1204. Similarly, thisassembly incorporates a cover 1142, the distal insertion portion 160 andthe tip retaining member 1170 as well as an interface stud 1150 andthreadingly retained retaining ring 1190 extending downwardly into thenarrowed neck portion 1220. In lieu of the proximal housing member thatretains an optical window, the rear mounting (adapter interface) member1224 is disposed at the proximal end 1218 of the instrument head 1204.According to this embodiment, and similar to the design previouslydiscussed (see 180 at FIG. 1(a)), the rear mounting member 1224 has adefined mounting flange 1226 and an annular slot 1228 that is configuredto receive the interface member (smart device adapter) 1240 and attachedsmart device 1230, as shown in the assembled form previously shown inFIG. 24(b).

Sectioned views of the assembled instrument heads 1104, 1204 are shownin FIGS. 27 and 28. respectively. Referring to FIG. 27, the instrumenthead 1104 of the otoscope 1100, FIG. 21, enables an image of the medicaltarget (e.g., the tympanic membrane) to be seen through the proximal end1116 of the instrument head 1104 by viewing through the optical window1128 as supported by the proximal housing member 1180. This enablesviewing of the medical target (e.g. tympanic membrane) through theinterior compartment created by the innerformer 1140 and the distalopenings 1127, 1161 that are formed in the distal insertion portion 1160and speculum tip 1124, respectively.

With reference to FIG. 28, an optical assembly is disposed in theinterior of the instrument head 1204 of the otoscope 1200 according tothis exemplary embodiment. Portions of the optical assembly are retainedwithin a tubular member (also referred to throughout as a lens tube)disposed within the interior compartment created by the innerformer 1140including a plurality of optical elements, each aligned and disposedalong a defined optical or viewing axis of the device 1200 extendingbetween the distal and proximal ends 1212, 1216 of the instrument head1204. The specifics of the optical assembly are more specificallydescribed in a later portion of this description. As referred to herein,an “optical element” refers to lenses and prisms as well as field stops,aperture stops, polarizers, and any component used to directing ortransmitting light along the defined optical or viewing axis. As in theprior described versions of the physical assessment device 100, FIGS.1(a), 13(b), the optical assembly according to this exemplary embodimentproduces an entrance pupil distal relative to the distal most opticalelement of the optical assembly, creating a field of view that permitsthe entire tympanic membrane (about 7 mm for an average adult) to beseen all at one time.

A sealing member 1250 is further provided at the rear of the innerformer1140 as engaged within a formed annular groove 1187. The sealing member1250 provides an adequate seal to the formed interior compartment of theinstrument head 1204 in order to permit insufflation capability(insufflation port not shown in this view) and also preventing foggingof the retained optical elements.

Each of the otoscopic instrument heads 1104, 1204 depicted in FIGS. 27and 28 commonly include an illumination assembly that is disposed withinthe downwardly extending portion 1120, 1220 and more specifically theinterface stud 1150. The illumination assembly according to thisembodiment is more clearly shown in FIG. 33 and includes an LED 1270 asa light source. More specifically, the LED 1270 is disposed upon theupper surface 1272 of a printed circuit board 1274 that is electricallycoupled to a downwardly depending electrical contact 1278 biased by aspring 279 disposed within an internal sleeve 1280, the distal end ofthe electrical contact 1278 extending from an opening of a narrowedportion of the internal sleeve 1280 and proximate an opening 1285 formedin the bottom of the instrument head 1104, 1204. The LED 1270 isdisposed in relation to a condensing lens 1290 and the polished proximalend of a fiber optic bundle 1287, the latter of which is advancedupwardly about the innerformer 1140 and extends as a ringlet of opticalfibers (not shown) between the distal end of the distal insertionportion 1160 and the innerformer 1140 in order to emit light toward thetarget of interest.

In each of the above noted devices 1100, 1200 and as described, the pairof housing sections 1134, 1138 can be secured to one another atcorresponding mating edges by means of ultrasonic welding with a cover1142 being introduced at the top of the instrument head 1104, 1204.

With reference to FIGS. 29 and 30 and according to yet another exemplaryembodiment, instrument heads 1304, FIGS. 29, and 1310, FIG. 30 areshown. Each of these instrument heads 1304, 1310 are similar toinstrument heads 1104, 1204. Instrument heads 1304 and 1310 include apair of mating housing shell sections 1324, 1328 that are attached toone another using an intermediate member, herein referred to as a strap1340. For purposes of clarity, like structural components are hereinlabeled with the same reference numerals. The strap 1340 according tothis specific embodiment is a singular member made from a flexible, butstructural material and having an upper portion 1344 and a lower portion1348.

As shown more specifically in FIG. 31, the upper portion 1344 of thestrap 1340 is defined by a rounded interior surface 1346 configured andsized to wrap around the exterior of the respective first and secondhousing shell sections 1324, 1328 after the mating edges of the housingsections 1324, 1328 have been placed in intimate contact with oneanother. According to this embodiment, the housing shell sections 1324,1328 define respective halves of the instrument head 1304, 1310. Each ofthe housing sections 1324, 1328 includes a recess 1330 formed in theexterior surface into which the strap 1340 is received such that theexterior surface of the strap 1340 is substantially coplanar with theexterior surface of the mated housing sections 1324, 1328 when attached.

During assembly/manufacture, the inner edges of the pair of housingsections 1324, 1328 are placed in intimate contact and the strap 1340 issnap-fitted into place onto the instrument head 1304 via the recess1330. As shown in FIGS. 31 and 32, the lower extending portions 1348 ofthe intermediate strap 1340 each include an annular flange 1352 formedon an inner surface, as well as an annular shoulder 1356 formed at theend of each lower extending section 1348. Referring to FIG. 32, theannular flange 1352 of each lower extending section 1348 is retainedwithin an annular groove 1153 formed in the interface stud 1150 andsecured by means of the retaining ring 1190 by threading engagement withthe bottom of the interface stud 1150 of the instrument head 1304, theupper end of the retaining ring 1190 engaging the shoulder 1356.

With reference to FIG. 33-36, an illumination assembly is retainedwithin the downwardly extending portion 1120 of the instrument head1104. According to the depicted embodiment, the illumination assemblyincludes the LED 1270 attached in a known manner to a top or uppersurface 1272 of a printed circuit board 1274. Disposed above the LED1270 and printed circuit board 1274 is an integrated component 1420 thatserves to center and align the LED 1270 and also collimates the lightthat is emitted from the LED 1270. The outer edges 1275 of the printedcircuit board 1274 are retained upon an interior shoulder 1156 of theinterface stud 1150. As shown in the sectioned view of FIG. 34, theintegrated component 1420 is defined by a cylindrically shaped body 1422having an upper end 1426, a lower end 1430, and a set of externalthreads 1434 extending along the length of the integrated component1420. An interior flange 1438 is disposed at an intermediate distancebetween the upper and lower ends 1426, 1430 of the integrated component1420, the flange 1438 having respective and opposing top and bottomsurfaces 1442, 1446.

A domed portion 1450, which is provided at the center of the top surface1442 of the internal flange 1438, is axially aligned with the LED 1270and acts as a condensing lens. An annular ring 1458 extending downwardlyfrom the bottom surface 1446 of the interior flange 1438 is configuredand sized to surround the lens envelope of the LED 1270 and functions tocenter the domed portion 1450 with the LED 1270, thus minimizingdecentration between the LED 1270 and the domed portion 1450 and anyassociated losses in light transmission. The set of external threads1434 are configured to mate with corresponding internal threads 1460that are provided in the interface stud 1150 of the instrument head1104. This mating allows the integrated component 1420 itself to fastenthe printed circuit board 1274 into the interface stud 1150 and furtherensure a secure electrical contact between the printed circuit board1274 and the interface stud 1150. This securement further preventsingress of dirt and debris.

According to this particular embodiment, a series of notches 1468 areprovided in spaced relation along the upper end 1426 of the integratedcomponent 1420, as shown in FIG. 35. The notches 1468 are shaped andconfigured to accept protrusions provided in a complementary driving ortorqueing tool (not shown) for purposes of assembly. The printed circuitboard 1274 according to this embodiment further includes an outer groundring that makes intimate electrical contact with a metal stud. Thethreaded connection between the integrated component 1420 and theinterface stud 1150 of the instrument head insures a secure highpressure mating at this junction. As noted, the domed portion 1450collimates illumination from the LED 1270. Advantageously, the design ofthe integrated component 1420 serves to save manufacturing costs andlabor and also reduces tolerance build ups, as well as preventing orminimizing ingress of dirt and contaminants.

An embodiment depicting the interconnection between an instrument head1104 and instrument handle 1108 for the physical assessment device 1100of FIG. 21 is illustrated in the sectioned view of FIG. 37. As shown,the instrument handle 1108 is a substantially cylindrical member havingan upper or top end and an opposing lower end, as well as at least oneinterior compartment that is sized and configured to retain at least onebattery for powering the contained light source in the instrument head1104. It should be noted that similar connections are provided for theinstrument heads previously described in this application.

Each of the instrument heads 1104, 1204 such as those shown in FIGS. 27and 28 and having an LED 1270 as a contained light source can beinterchangeably attached to the instrument handle 1108 by means of abayonet connection between the top end of the instrument handle 1108 andthe narrowed neck portion of the instrument head 1104. Known physicalassessment devices, such as those commercially sold by Welch Allyn, Incprovide a bayonet connection between the instrument head and theinstrument handle. More specifically, a set of spaced lugs are providedon the top of the instrument handle that engage a corresponding slotformed in the lower end of the instrument head when the instrument headis twisted in a predetermined direction.

As noted, each of the previously described instrument heads, includinginstrument heads 1104, 1204 or 104, FIG. 13(b), 104A, FIG. 5(a), includean LED as a light source for the contained illumination assembly.

There is a need with the evolution of LEDs as light sources in physicalassessment devices to prevent instrument handles, especially those wiredto wall mounted systems that will not power instrument heads equippedwith halogen lamps. Halogen lamps draw large currents and the associatedvoltage drop through wall unit power cords. This voltage drop makescompliance with safety standards difficult and forces the furtherinclusion of expensive electronics. LED systems, on the other hand, drawrelatively small currents and do not have this drawback. As instrumentheads evolve and utilize LED as illumination sources, it is anticipatedthese instrument heads can be used with existing instrument handles.However and as wall mounted systems also evolve, it is a desire toprevent the use of existing instrument heads having halogen lamp lightsources.

With reference to FIGS. 37-43, an embodiment is herein described toenable an instrument handle to be incompatible with certain instrumentheads (i.e. those having halogen lamps). With reference to FIG. 38, aninstrument handle 1602 includes a top portion 1604. A pair of equallyspaced male lugs 1612 are provided on the exterior of the top portion1604 of the instrument handle 1602. Each lug 1612 according to thisembodiment is defined by a width dimension denoted by arrows 1616 thatenables the lug 1612 to be fitted within a defined bayonet slot of amated instrument head.

An instrument head 1620 is shown in FIGS. 39 and 40. In this instance,the physical assessment device is an ophthalmoscope, but the principleis common to other physical assessment devices, such as the previouslydescribed otoscopes. The mating connection is provided at the bottom ofthe instrument head 1620 and includes an interface stud 1624 whosebottom end 1628 is defined with a contoured slot 1632 to provide asecure locking engagement when the instrument head 1620 is rotatedrelative to the instrument handle 1602 by means of a bayonet connection.

The assembled interface is shown more clearly in FIGS. 41 and 42 witheach of the spaced lugs 1612 of the instrument handle 1602 engagedwithin the contoured mating slot 1632 of the instrument head 1620. Inthis mounted position, the electrical contacts 1640, 1646 of theinstrument head 1620 and the instrument handle 1602 are positioned intocontact with one another. For purposes of this embodiment and referringto FIG. 42, the width dimension of the contoured mating slot 1632 isincreased enabling interchangeability between various instrument headsand handles. With reference to FIG. 43, the width dimension of themating lugs 1612 of the instrument handle 1602 can be increased suchthat the lugs 1612 will not fit within the mating slot (not shown) of analready existing ophthalmic instrument head having a halogen lightsource.

Referring to FIG. 44, an exemplary instrument handle 1706 is shownhaving a upper end 1707 including a top portion 1709 and an opposingbottom end 1711. A partially sectioned view of the upper end 1707 of theinstrument handle 1706 is further depicted in FIG. 45. Morespecifically, the upper end 1707 includes a rheostat assembly 1712 thatselectively adjusts the level of illumination of the retained lightsource, such as the at least one LED 1270, FIG. 33, when the instrumenthead (not shown) is attached to the instrument handle 1706. Thisconnection is made using bayonet engagement features provided on each ofthe mated components such as those previously discussed. When connected,the LED 1270, FIG. 33, is powered through coupling between the retainedbattery 1714 (partially shown in FIG. 45), the rheostat assembly 1712,the electrical contact 1717 biased by spring 1721 and the electricalcontact 1640, FIG. 40, in order to electrically couple the LED 1270,FIG. 33, with the battery 1714.

Referring to FIGS. 45-48 and according to one embodiment, the rheostatassembly 1704 includes a twistable grip section 1718 that is provided onthe exterior of the instrument handle 1706. The twistable grip section1718 is disposed over a cylindrically shaped detent ring member 1722having a series of holes 1726 arranged along its periphery proximate alower end 729 of the detent ring member 1722, as shown more clearly inFIG. 47. A pin member 1732 extends within an annular recess 1734 formedin the detent ring member 1722 and is biasedly retained within a recess1736 formed in an internal sleeve 1750. A ball 1740 is also biasedlyretained in an opening formed in the internal sleeve 1750 which isdiametrically opposite that of the pin member 1732. The ball 1740 isconfigured to rotate with the twistable grip section 1718 and is causedto extend into one of the holes 1726 in the detent ring member 1732, thelatter being stationary to create an audible and tactile sensation forthe user. Each of the ball 1740 and the pin member 1732 are biased bysprings 1744, 1748 which are disposed within the diametrically opposedopenings in the internal sleeve 1750 extending in a direction that istransverse to a primary axis of the instrument handle 1706. The detentring member 1732 includes the set of interior threads 1725 that engage acorresponding set of external threads 1757 provided on a rheostathousing 1758.

In operation, the twistable grip section 1718 rotates around thestationary detent ring member 1722. The pin member 1732 keys into thetwistable grip section 1718 and rotates with the grip section 1718 whentwisted by a user. The spring-loaded ball 1740 also rotates with thetwistable grip section 1718 and depending on the rotational position ofthe grip section 1718 detents into one of the series of holes 1726provided in the stationary detent ring member 1722. Attributes of thespring 1748 biasing the ball 1740 can be suitably varied as needed inorder to provide a desired detent release force. The foregoing providesaudible and tactile feedback about the location of the rheostat. Thisfeature allows a user of the instrument to create a preferred settingwhich can repeated to obtain a consistent amount of light with each use.The detent positions and size and configuration of the detent stops canbe altered in order to provide a different sound or release strength atdifferent or selected positions, such as the zero position or otherrheostat position.

With reference to FIGS. 48 and 49, the instrument handle 1706 can beequipped with a USB charging or power boosting port 1760. According tothis embodiment, the USB port 1760 is provided on the exterior of theinstrument handle 1706 and proximate the bottom or lower end 1711. Itwill be understood, however, that the location of this port 1760 can besuitably varied relative to the instrument handle 1706. With referenceto the sectioned view of FIG. 49 and according to this embodiment, thecharging port 1760 extends to a USB connector 1768 mounted to the topsurface of a printed circuit board 1772 that is disposed within theinterior of the instrument handle 1706 in which contacts extend to thecontained battery 1714 (partially shown in this view). According to thisembodiment, a set of electrical charging contacts axially extend fromthe lower end 1709 of the instrument handle 1706 enabling the instrumentto be used in conjunction with a charging base or cradle 1800, FIG. 52,that enables the at least one contained battery 1714 to be recharged.

According to this embodiment and with reference to FIGS. 49 and 50, apositive contact 1777 extending from the lower end 1709 of theinstrument handle 1706 is soldered to the printed circuit board 1772 viaa connection 1779 and a conductive spring clip 1782 is provided to serveas a negative contact connecting an outer ring 1713 at the bottom end1711 of the instrument handle 1706 with the printed circuit board 1772,the latter being electrically coupled to the lower contact end of thebattery 1714. As such, the herein described instrument handle 1706 canbe configured with dual charging modes.

The norm in the medical industry is to charge the instrument handle(power source) through either a desk charger or more recently using USB.With reference to FIG. 50, a circuit is depicted that allows one or moreinstrument handles to be charged through a desk charger, such as base1800, or the USB charging port 1760. This charging circuit uses acharging IC and accepts power from either a USB input or via positiveand negative contact pins.

FIG. 51 illustrates a sectioned view of the alternative charging modewith the electrical contacts 1777 and 1782 being coupled to respectivecharging pins 1809 that are provided within a charging well 1814 of thecharging base 1800, which is only partially shown in this view.

FIG. 52 provides a perspective view of a charging base 1800 made inaccordance with an embodiment and including a pair of charging wells1814 extending from a top surface 1811. Each of the charging wells 1814are sized to receive an instrument handle 1822, 1832 of a physicalassessment device 1820, 1830 and provide a stable base, the chargingwells 1814 having a defined height that creates a stable base for theretained physical assessment devices 1820, 1830. With continuedreference to FIG. 52, a pair of physical assessment devices 1820, 1830and more specifically, an ophthalmoscope and an otoscope are commonlyretained in separate charging wells 1814 of the charging base 1800 inwhich each of the retained devices 1820, 1830 includes an attached smartdevice 1828, 1838, such as a smart phone. The two physical assessmentdevices 1820, 1830 are mounted at the same time, as shown, with therespective instrument handles 1824, 1834 being inserted into thecharging wells 1814 such that the retained smart devices 1828, 1838 areopposed to one another. In this mounted position, there is with nointerference between the mounted devices or between either retainedphysical assessment device 1820, 1830 and the charging base 1800.

According to one version and as shown in FIG. 53, a thermistor,thermocouple 1790 or other temperature determining apparatus can extendfrom the printed circuit board 1772 within the instrument handle 1706 byconnection 1792 and be disposed in relation with the contained battery1714. The output of the thermistor 1790 provides direct batterytemperature measurement during charging and discharging of the battery1714 which can further be coupled to an indicator (not shown) on thecharging base 1800, FIG. 52, or the instrument handle 1706. As such,potential overheating of a contained battery, such as an alkalinebattery, can be monitored.

Due to the fact that both halogen lamp based and LED-based instrumentheads may be used interchangeably, instrument handles should be designedso as to prevent overheating of a contained alkaline battery, especiallyif a halogen-based instrument head is attached.

An example of an electrical circuit intended to solve this problem isdepicted in FIG. 53, preventing overheating of a contained battery. Theelectrical circuit employs a voltage boost design with input currentlimit (such as Texas Instruments TPS 61251). With this circuit's design,a current limit can be set on the voltage boost IC so that if a halogenbased lamp is connected to the instrument handle having an alkalinebattery, the current will be limited and not exceed the battery's limitthat would cause overheating.

In addition, this voltage boost IC will enable improved performance ofan instrument head that is equipped with an LED as a light source andsubsequent use of LED replacement lamps.

As discussed, the interior of at least one of the herein describedinstrument heads 104, FIG. 2(b), FIGS. 13(b) and 1204, FIG. 28, canretain an optical system or assembly that includes a plurality ofcomponents aligned along an optical or viewing axis extending throughthe distal end opening 124, 1125 of the hollow speculum tip element 120,1124, which is releasably attached to the instrument head 104, 1204 andcontinuing through the interior of the instrument head 104, 1204,passing through the proximal end 1014, 1216 thereof.

Reference is herein made to FIG. 54(a), which depicts a ray trace of theoptical system or assembly 1900 of the physical assessment device 100,FIGS. 2(b) and 13(b) and FIG. 54(b), providing a comparison betweenthree (3) additional optical assemblies 1910, 1940 and 1950 for anexemplary instrument head, including that of instrument head 1204. Thebottommost optical assembly 1910 depicted is representative of a knownoptical assembly which is fully described in U.S. Pat. No. 7,399,275,and incorporated herein by reference in its entirety.

First and with reference to FIG. 54(b), the known optical assembly 1910includes a distal objective lens doublet 1914 that would be disposedproximate the distal opening of the distal insertion portion 1160, FIG.28, of the instrument head 1204 having an attached speculum tip element1124. A pair of aligned relay lenses 1919, 1922 are disposed proximallyto the objective lens doublet 1914, as well as an aperture plate 1920disposed between the pair of relay lenses 1919, 1922. A set of eyepiecelenses 1930 is disposed proximally from the second relay lens 1922, eachaligned along a defined optical axis. This optical assembly 1910produces an entrance pupil (shown as 1934) that is proximate to, butdistal relative to the objective lens doublet 1914, and creating a fieldof view that enables the entire tympanic membrane to be viewed all atone time at the image plane of the clinician's eye, if viewed optically,or the image plane of an attached digital imager (not shown). Morespecifically, this optical assembly 1910 produces a field of view ofabout 9 mm at a working distance (distance between the distalmost opticand the patient) of about 33 mm, which allows the entire tympanicmembrane (about 7 mm) to be viewed all at one time. Though this opticalassembly 1910 is highly effective due to the increased field of view,the resulting image is influenced by the attached speculum tip 1124, asshown in the top illustration of FIG. 55.

Referring to FIG. 54(b), two other optical assemblies 1940 and 1950 areshown and compared to optical assembly 1910 as well as FIG. 54(a), whichillustrates the optical assembly 1900 of instrument head 100, FIG. 2(b),FIG. 13(b). More specifically, the optical assembly 1940 includes inorder and arranged from distalmost to proximalmost: an objective lens1941, relay lens 1942, field stop 1945, imaging lens 1943 and a planowindow 1944. The optical assembly 1950 is similarly defined startingfrom the distal end and moving toward the proximal end by an objectivelens 1967, relay lens 1968, a field stop 1971, an imaging lens doublet1969 and a plano window 1970. The optical assembly 1900, FIG. 54(a) issimilar to the optical assembly 1950 and is defined by the followingelements from distalmost to proximalmost: an optical window 161 disposeddistally relative to an objective lens 160 separated by a field stop164, FIG. 4, that reduces light scatter, a relay lens 166, an apertureplate 167, FIG. 4, a field stop 170, FIG. 4, an imaging lens 169 and awindow 189 provided at the proximal end of the assembly 1900.

The optical components of each of these optical assemblies 1900, 1940,1950 are also configured to create an entrance pupil that is distal fromthe distalmost optical element 160/161, 1941, 1967, respectively.

The overall effect is shown in the schematic comparative view depictedin FIG. 55, contrasting the known optical system 1910 with opticalassemblies 1900 and 1950 in which each optical assembly is disposedwithin the instrument head 1204 for purposes of comparison. A similarfield of view is created by each of the optical assemblies 1900, 1950,but the distal entrance pupil 1966 created by each of the latter opticalassemblies 1900, 1950 is moved distally toward the patient, as comparedwith that of the distal entrance pupil 1934. Consequently, the cone oflight rays does not chop the attached speculum tip element 1124 andenabling the tympanic membrane to still be viewed all at one time by thecaregiver, but without any portion of the speculum tip element 1124being in the resulting image.

Surprisingly and resulting from the above optical system, Applicantshave further discovered that the attached speculum tip element can bemade optically clear, as opposed to the typical black opaque versions ofthese elements. The resulting light spot produced is clear, crisp andwell defined without edge effects.

Another alternative optical assembly 1980 is depicted schematically inFIG. 56 based on a change in materials that produces a similar overalleffect (distal entrance pupil 1966, FIG. 55) upon a resulting image ofthe medical target. In the optical assemblies 1900 and 1950, each of theoptical elements are made from a moldable plastic, while the opticalelements according to this latter optical assembly 1980 are made fromglass. More specifically, two (2) glass lenses are used in place of aplastic aspheric lens for each of the objective lens 1982, relay lens1984 and eyepiece lens 1986 wherein the two glass lenses achieve imagequality by two facing plano-convex lenses of high index of refraction(greater than 1.80) and abbe value greater than 35. The optical assembly1980 further includes a plano window 1988. It will be understood thatsimilar configurations are possible.

Ophthalmoscope

The following portion of the description relates to the design ofanother physical assessment device that is made in accordance withvarious exemplary embodiments. More specifically, the physicalassessment device is an ophthalmic device that is configured forexamining the eyes of a patient. It will be understood, however, tothose in the field that certain of the inventive aspects describedherein can be applied to various other medical examination or diagnosticdevices.

With reference to FIGS. 57(a) and 57(b), the ophthalmoscope 2000includes an instrument head 2004 that is releasably supported to theupper end of a handle or handle portion 2008 using a bayonet or similarconnection, the handle portion 2008 enabling the instrument 2000 to beportable and configured for hand-held use. The handle portion 2008includes at least one contained battery (not shown) for powering a lightsource (i.e., an LED—not shown) provided in the instrument head 2004. Inaddition, a rheostat 2020, which includes a rotatable portion of thehandle portion 2008 is configured to control the amount of illuminationof the light source, as well as a depressible on-off button 2022. Thecontained battery is preferably rechargeable, wherein the lower portionof the handle portion 2008 includes a charging port 2024.

The instrument head 2004 is defined by a distal (patient) end 2010 andan opposing proximal (caregiver) end 2014, and further defined by aninterior that is sized and configured to retain a plurality ofcomponents. As described in greater detail below, the distal end 2010 ofthe instrument head 2004 receives a deformable eye cup 2030, while theproximal end 2014 of the instrument head 2004 includes an adapterinterface member 2040, similar to the adapter interface member 180,FIGS. 2(a), and 1224, FIG. 30, to enable releasable attachment of asmart device adapter 300, FIGS. 6-13(b). The instrument 2000 furtherincludes a rotatable diopter wheel 2050 supported between mating frontand rear housing sections 2210 and 2214, as well as an rotatableaperture wheel 2060, the latter being disposed in a lower portion of theinstrument head 2004 and having a portion of the aperture wheel 2050extending outwardly from a formed slot that is provided in the fronthousing section 2210.

An optical assembly and an illumination assembly are commonly retainedwithin the interior of the instrument head 2004. According to thisexemplary embodiment and with reference to FIGS. 58, 59(a) and 59(b),the distal most component of the optical assembly is an objective lens2240, which is mounted adjacent the distal end 2010 of the instrumenthead 2004. The rear peripheral edge 2242 of the objective lens 2240 issecured against an annular shoulder 2245 formed in the instrument head2004 and held in position by means of an end cap 2248 that isthreadingly positioned onto the distal end of the front housing section2016, the latter having a corresponding set of threads 2249. Whensecured, the end cap 2248 also is configured to retain a fixation targetretainer 2254, the latter of which is peripherally disposed about theobjective lens 2240. An O-ring 2260 creates a seal between the objectivelens 2240 and the fixation target retainer 2254.

Angled slots are provided on a front facing surface of the fixationtarget retainer 2254 that receive polarizer windows 2256, (shown only inthe exploded FIG. 58) which according to this embodiment can be formedof different colors (i.e., blue, red) for directing a pair of fixationtargets to the patient. The polarizer windows 2256 are positioned at thedistal (objective) end 2010 of the instrument head 2004 with slots beingdisposed on diametrically opposite (left/right) sides of the objectivelens 2240 where the fixation illumination targets are located. When thepatient looks at the fixation target in the opposite direction relativeto the eye being examined (that is, the right eye looking at the lefttarget or the left eye looking at the right target), the patient's eyewill align at approximately 17 degrees positioning their optic disc nearthe center of the view. According to this embodiment, a set of opticalfibers (not shown), preferably having polished ends, extend from acontained LED 2356 of the illumination assembly of the ophthalmoscope2000 to each of the fixation targets. More specifically, the polisheddistal end of the optical fibers are placed in contact with thepolarizer windows 2256, with the fibers being routed through theinterior of the instrument head 2004 upwardly from the LED 2356, thelatter of which is retained in the lower portion of the instrument head2004. According to this embodiment, the proximal end of the fixationtarget fibers are disposed on lateral sides of the LED 2356, althoughother suitable configurations can be utilized to direct the requiredillumination efficiently to the distally disposed fixation targets.

The proximal end of the eye cup 2030 is disposed over the distal end2010 of the instrument head 2204 and about the contained objective lens2240 to create the proper working distance between the physicalassessment device 2000 and the eye of the patient, which according tothis embodiment is approximately 25 mm. The eye cup 2030 is made from anelastomeric material and is shaped and configured to allow the distalend of the eye cup to be placed over the eye of the patient. Theproximal end of the eye cup 2030 includes at least one internalengagement feature and is shaped to be releasably and securely attachedto the end cap 2248, the latter also being suitably shaped andconfigured for this engagement.

At the proximal end 2014 of the instrument head 2004, the containedoptical assembly includes an eyepiece holder 2270 projecting outwardly(proximally) from the instrument head 2004 and contained within theadapter interface member 2040. According to this embodiment, theeyepiece holder 2270 is defined by an open-ended structure that retainsa pair of eyepiece lenses 2280, 2284 each separated an appropriatedistance by an intermediate eyepiece spacer 2288. The eyepiece lenses2280, 2284 are retained proximally relative to a field stop holder 2290in which the eyepiece holder 2270 is threadingly engaged within anopening formed in the adapter interface member 2040. A field stop 2297is retained within a narrowed portion 2299 of the field stop holder2290, which is aligned with the eyepiece lenses 2280, 2284 and theobjective lens 2240 along a defined optical axis of the device 2000.

Disposed between the proximal and distal ends 2010, 2014 of the hereindescribed physical assessment device 2200 is a relay lens 2286 that isaligned along the defined viewing axis, as well as an aperture stop2291, each of the foregoing optical components being intermediatelydisposed within the interior of the instrument head 2004 as part of theoptical assembly. The relay lens 2286 is retained within a relay lensholder 2287 and more specifically within an aperture that is sized toretain the relay lens 2286 and aligned with the remaining opticalcomponents along the defined optical axis. A polarizer window isdisposed immediately distal to the supported relay lens 2286. The relaylens holder 2287 is attached to a proximal end of a top optical basemember 2426.

Regarding the illumination assembly and with reference to FIGS. 58,59(a) and 59(b), the instrument head 2004 further retains a plurality ofcomponents configured for illuminating the patient's eye. An electricalcontact pin 2320 is disposed within a hollow plastic insulator 2328, thelatter having an upper portion which is sized and configured to retain acoil spring 2332 for biasing the contact pin 2320. The coil spring 2332is preferably disposed between a top or upper end of the contact pin2320 and a shoulder formed in an upper portion of the insulator 2328.

When a lowermost end of the contact pin 2320 is engaged with electricalcontacts (not shown) in the handle (not shown) of the physicalassessment device 2000, the top end of the contact pin 2320 is pressedinto contact with a lower surface of a printed circuit board 2350 for anLED 2356 that is disposed on the upper surface of the circuit board2350. The circuit board 2350 is positioned in place onto a circuit boardretainer 2330 that further retains the insulator 2328 and contact pin2320, the circuit board retainer 2330 having a set of external threads2331 that engage a set of corresponding threads that are provided withinan optical base member 2390. As discussed herein, the circuit board 2350can be configured with an LED drive circuit that is compatible withdifferent instrument handles, including those typically configured fordriving incandescent light sources. This circuitry is described in alater portion of this application.

For purposes of this embodiment, the LED 2356 is aligned with acondenser lens 2364 along a defined illumination axis, the condenserlens 2364 being retained within a lens holder 2380 that is snapfitted ina manner that creates alignment with the LED 2356. Each of these lattercomponents are further retained within the optical base member 2390, inwhich the optical base member 2390 is fitted within a lower neckedportion of the instrument head 2004.

According to this embodiment, the aperture wheel 2060 is disposed abovethe condenser lens 2364 and supported for rotation by the optical basemember 2390. A slot is provided in the front housing section 2016 topermit access to the aperture wheel 2060, which is configured forrotational movement in order to selectively position each of a series ofcircumferentially spaced apertures formed on an aperture plate 2404 intoalignment with the LED 2356 and condenser lens 2364 along the definedillumination axis. A pair of cover sections 2062, 2064 retain therotatable aperture wheel 2060 within a recessed portion of the opticalbase member 2390. The cover portions 2062, 2064 retain ends of an axle2065 that extends through the center of the aperture wheel 2060 and theaperture plate 2404, enabling rotation. More specifically, a pluralityof windows are circumferentially disposed on the aperture wheel 2060that may include a red free filter, a blue filter, as well as varyingsized apertures. Various other configurations can easily be realized.

Above the aperture wheel 2060 and the optical base member 2390, theillumination assembly further includes a relay lens 2420, whichaccording to this exemplary embodiment is retained within the upper endof the optical base member 2390 and aligned with the condenser lens2364, the rotatable aperture wheel 2060, and the LED 2356 along thedefined illumination axis.

A polarizer window 2440 is retained at the top surface of the opticalbase member 2390 above and distally relative to the relay lens 2420 andin relation to a mirror 2450, the latter being supported by a mirrormount assembly 2453. A compression spring 2395, FIG. 60(a), providedbetween the top optical base member 2426 and the upper portion of theoptical base member 2390 maintains pressure against the polarizer window2440 and relay lens 2420 of the illumination assembly in which the lowerend of the optical base member 2426 is accommodated, but not secured,within an upper portion of the optical base member 2390. The foregoingarrangement further maintains the alignment of the relay lens 2286 andrelay lens holder 2287 of the optical assembly of the herein describeddevice 2000, each of which are retained within the top optical basemember 2426 as previously discussed.

With reference to FIGS. 58, 59(b), and 60(a)-60(d), the mirror mountassembly 2453 includes a elongate mirror mount 2454 having an upper end2455 and a lower end 2456. The lower end 2456 of the mirror mount 2454retains the mirror 2450 along an inclined support surface 2451. Themirror mount 2454 is pivotally supported within an enclosure 2458 thatis provided within the top optical base member 2426. An adjustmentmember 2462, such as a threaded fastener, extends into a formed slot inthe rear housing section 2018 of the instrument head 2004 and furtherextends into an upper section of 2459 of the enclosure 2458. The distalend of the adjustment member 2462 is configured to engage a rear facingsurface 2457 at the top of the mirror mount 2454 in order to cause themirror mount 2454 to pivot and enable the angle of the supported mirror2450 to be adjusted to direct light from the LED 2356, FIG. 59(b),toward the distal end of the instrument head 2004.

A block 2466 of a elastomeric material, such as poron, is also fittedwithin the top of the enclosure 2458 immediately adjacent a front facingsurface of the mirror mount 2454 against which the adjustment member2462 engages. With reference to FIG. 60(c), the enclosure 2458 accordingto this embodiment is defined by a substantially cylindrical upperportion 2459 and a pair of lower extending legs 2460, the latter whichretain the lower end 2456 of the mirror mount 2454 through a pinnedconnection. The upper end 2459 of the enclosure 2458 includes a threadedsleeve 2461 aligned with the rear facing surface 2457 of the top of themirror mount 2454 that receives the adjustment member 2462. Theenclosure 2458 according to this embodiment is supported within the topoptical base member 2426 along with a sealing member, such as an O-ring2470. According to this embodiment, the adjustment member 2462 furtherpermits lateral adjustments of the retained mirror 2450 in addition toangular (pivotal) adjustments of the mirror mount 2454, wherein theO-ring 2470 contacting the inner surface of the optical base member 2426provides sufficient resistance to maintain the lateral adjustment of thesupported mirror 2450.

Referring to FIGS. 59(b), the illumination assembly allows light fromthe contained LED 2356 to be directed through the aligned condenser lens2364, the aperture wheel 2060, the relay lens 2420 and the polarizerwindow 2440 to the supported mirror 2450 along the defined illuminationaxis. A reticle (not shown) can further be provided as part of theaperture wheel or otherwise within the optical base member. The light isthen further directed toward the distal end 2012 of the instrument head2004 and more specifically through the objective lens 2240 and in whichthe light is focused at the edge of the pupil of the patient's eye. Theposition of the objective lens 2240 can be suitably adjusted at the timeof manufacture to further offset any tolerance mismatches in addition tothe adjustment of the supported mirror via the mirror mount assembly.

Referring to FIG. 59(a), light reflected from the back of the patient'seye is directed into the distal end of the ophthalmoscope 2000 throughthe objective lens 2240 in which the light is then focused onto therelay lens 2286, which directs the light through the field stop 2297 andthe imaging lenses 2280, 2284 to the clinician's eye (not shown) or toan attached smart device attached to the adapter interface member 2040.The adapter interface member 2040 according to this embodiment isstructurally similar to the adapter interface member 180, FIGS. 6-13(b),and does not require additional discussion.

Variations—Ophthalmoscope

As shown in FIG. 61, an ophthalmoscope 3100 made in accordance withanother exemplary embodiment is herein described. As discussed hereinand shown in FIG. 65, the ophthalmoscope 3100 includes an instrumenthead 3104 that is releasably attached to the upper end of a handleportion 3108. The instrument head 3104 is defined by a distal (patient)end 3112 and an opposing proximal (caregiver) end 3116. The interior3105 of the instrument head 3104 is sized and configured for retainingan illumination assembly 3101 and an optical assembly 3102.

According to this version and as shown in FIGS. 62 and 63, an eye cup3120 is attached to the distal end 3112 of the instrument head 3104.According to this embodiment, the eye cup 3120 is a flexible component,preferably made from an elastomeric material that is designed for directengagement with the patient. When attached, the eye cup 3120 establishesa working distance between the patient's eye and a first distalmost lenscomponent of a contained optical assembly.

The eye cup 3120 according to this embodiment is defined by a solidcontiguous member. In an alternative embodiment, the eye cup can includeone or a plurality of slits or openings (not shown) that do notsacrifice structural integrity for purposes of patient alignment.

In accordance with an embodiment and as shown in FIGS. 64(a) and 64(b),a disposable ring member 3124 can be provided which is configured andsized to fit within the distal end opening 3122 of the eye cup 3120.More specifically, the disposable ring member 3124 is defined by aflexible material, such as, for example, a foam material orpolypropylene and defined by opposing distal and proximal end openings3125, 3127 in which the distal end opening 3125 includes an annularouter flange 3129. When attached, the disposable ring member 3124 can beinserted into the distal end opening 3125 of the eye cup 3120 with theannular outer flange 3129 of the disposable ring member 3124 creating astop.

According to one embodiment, a user can load the disposable ring member3124 from a stacked set of rings (not shown) in a container (not shown)having an open top and engaging the distal end of the eye cup 3120 withthe disposable ring member 3124 until the distal end of the eye cup 3120engages the annular outer flange 3129 of the disposable ring member3124. Compression of the eye cup 3120 creates positive engagementbetween the inner portions of the eye cup 3120 and the outer surface ofthe disposable ring member 3124, allowing the disposable ring member3124 to remain attached to the eye cup 3120 when the eye cup 3120 isremoved from the container. Advantageously, the disposable ring member3124 can be attached without having to touch the ring member 3124 andwherein the disposable ring member 3124 permits reuse of the eye cup3120 as shown. The disposable ring member 3124 also serves as a stop,preventing eye cup 3120 from fully compressing against a patient's eye.

With reference to the sectioned view of FIG. 65, the instrument head3104 according to this embodiment is manufactured using a two-parthousing made up of a front housing section 3109 and a rear housingsection 3110 that are mated together. The instrument head 3104 isdefined by an interior 3105 that is sized and configured for retaining aplurality of components, including an optical assembly 3101 and anillumination assembly 3102. As shown schematically according to FIGS.66-68, the optical assembly 3101 includes a plurality of opticalcomponents or elements disposed and aligned along a defined viewing oroptical axis 3132 that extends through the eye 3130 of the patient, aswell as the distal and proximal ends 3112, 3116 of the device 3100. Aspreviously referred to herein, an “optical component” or “opticalelement” refers to lenses and prisms as well as field stops, aperturestops, polarizers, and any component used to directing or transmittinglight along a defined optical or viewing axis.

According to this embodiment, the distal most component of the opticalassembly is an objective lens 3140, which is mounted adjacent the distalend 3112 of the instrument head 3104. As shown in FIG. 65, the rearperipheral edge 3142 of the objective lens 3140 is secured against anannular shoulder 3145 formed in the instrument head 3104 and held inposition by means of an end cap 3148 that is threadingly positioned tothe distal end 3112 of the instrument head 3104. When secured, the endcap 3148 also is configured to retain a fixation target retainer 3154,the latter of which is peripherally disposed about the objective lens3140 and as further shown in FIG. 69. Angled slots are provided on afront facing surface of the fixation target retainer 3154 that receivepolarizer windows which according to this embodiment can be formed ofdifferent colors (i.e., blue, red) for directing a pair of fixationtargets to the patient.

As shown in FIG. 69, the objective end of the instrument head 3104 isshown with two slots on each side (left/right) of the lens 3140 wherethe fixation illumination targets are located. When the patient looks atthe target in the opposite direction relative to the eye being examined(that is, the right eye looking at the left target or the left eyelooking at the right target), the patient's eye will align atapproximately 17 degrees positioning their optic disc near the center ofthe view. According to this embodiment, a set of optical fibers,preferably having polished ends, extend from the contained LED to eachof the fixation targets. More specifically, the polished distal end ofthe optical fibers are placed in contact with the polarizer windows,with the fibers being routed through the interior of the instrument headand downwardly to the contained LED. According to this embodiment, theproximal end of the fixation target fibers are disposed on lateral sidesof the LED, although other configurations can be utilized.

The proximal end of the eye cup 3120 is disposed over the distal end3112 of the instrument head 3104 and about the contained objective lens3140 to create the proper working distance between the device 3100 andthe patient, schematically shown in FIG. 66, which according to thisembodiment is approximately 25 mm.

The proximal end 3116 of the instrument head 3104 includes an eyepieceholder 3170 projecting outwardly (proximally) from the instrument head3104. According to this embodiment, the eyepiece holder 3170 is definedby an open-ended structure including an annular shoulder 3172 formed onan outward (proximal) facing side, which is sized and configured toretain a brow rest 3176 for use by the clinician. The eyepiece holder3170 retains a pair of eyepiece lenses 3180, 3184 that are separated anappropriate distance by an eyepiece spacer 3188. The eyepiece lenses3180, 3184 are retained in a field stop holder 3190 that is threadinglyengaged within an opening formed in the eyepiece holder 3170 and theinstrument head 3104. A field stop 3197 is retained within a narrowedportion 3199 of the field stop holder 3190 and aligned with the eyepiecelenses 3180, 3184 and the objective lens 3140 along the defined opticalaxis.

Disposed between the proximal and distal ends 3112, 3116 of the device3100 and referring to FIGS. 65-68, the herein described optical assembly3101 further includes a relay lens 3186 that is aligned along thedefined viewing axis 3132, as well as an aperture stop 3191, eachintermediately disposed within the interior 3105 of the instrument head3104.

The components of the optical assembly 3101 are shown in respectivelayouts presented according to FIG. 66-68, which includes the objectivelens 3140, the aperture stop 3191, relay lens 3186, field stop 3197 andeyepiece lenses 3180 and 3184, each aligned along the viewing axis 3132relative to the clinician's eye (not shown) as brought to the brow rest3176 or as shown in FIG. 62, relative to the interface and imagingaperture of an attached smart device 3106.

Regarding the illumination assembly 3102 and with reference to FIG. 70,the lower necked portion 3107 of the instrument head 3104 includes aplurality of components configured for illuminating the target (eye) ofinterest. An electrical contact pin 3220 is disposed within an opening3224 formed in a plastic insulator 3228, the latter having an upperportion 3229 that retains a coil spring 3232 for biasing the contact pin3220. The spring 3232 is disposed between a top or upper end 3224 of thecontact pin 3220 and a shoulder 3238 formed in the upper portion 3229 ofthe insulator 3228.

When a lowermost end of the contact pin 3220 is engaged with electricalcontacts (not shown) in the handle (not shown) of the physicalassessment device 3100, the top end 3224 of the contact pin 3220 ispressed into contact with a lower surface of a printed circuit board3250 for an LED 3256 that is disposed on the upper surface of thecircuit board 3250, shown most clearly in FIG. 70. The circuit board3250 is positioned in place onto a circuit board retainer 3230 thatfurther retains the insulator 3224 and contact pin 3220, the retainer3230 having a set of external threads that engage corresponding threadsprovided within an assembly support member 3290.

The LED 3256 is aligned with a condenser lens 3264 along an illuminationaxis 3310, FIG. 66, the condenser lens 3264 being retained within a lensholder 3280 that further retains a centering ring 3281 aligned with theLED 3256. Each of these latter components are further retained withinthe assembly support member 3290, the assembly support member 3290 beingfitted within the lower necked portion 3107, FIGS. 65, 70, of theinstrument head 3104.

Referring to FIGS. 65 and 70, an aperture wheel 3300 is disposed abovethe condenser lens 3264. The aperture wheel 3300 is supported by theassembly support member 3290 and configured for rotational movement soas to selectively locate and position each of a series ofcircumferentially spaced apertures formed on an aperture plate 3304 intoalignment with the LED 3256 and condenser lens 3264 along the definedillumination axis 3310, FIG. 67. More specifically, a plurality ofwindows 3304 are circumferentially disposed on the aperture wheel 3300that include a red free filter, a blue filter, as well as varying sizedapertures. It will be readily apparent that various other configurationscan easily be realized.

With reference to FIGS. 65 and 67 and above the aperture wheel 3300 andthe assembly support member 3290, the illumination assembly furtherincludes a relay lens 3320 which according to this embodiment isretained in a holder 3326. According to this embodiment, the relay lensholder 3326 is threadingly secured to an upper portion of the assemblysupport member 3290 and aligned with the condenser lens 3264, aperturewheel 3300, and the LED 3256 along the defined illumination axis 3310.

With reference to FIGS. 66-68, the optical and illumination assemblycomponents of this physical assessment instrument are illustrated inschematic form for the sake of clarity. As noted, the optical assembly3101 includes the objective lens 3140 aligned with eyepiece lenses 3180,3184 and the field stop 3197, as well as the relay lens 3186 and theaperture stop 3191, each of which are aligned along the defined opticalaxis 3132. In addition, a diopter wheel 3200 supports a plurality ofoptical elements 3204 of varying power (concave/convex). The diopterwheel 3200 is rotatably movable into and out of the defined viewing axis3132 for purposes of establishing the focus of the patient's eye 3130.

Still referring to FIG. 67, the illumination assembly 3102 comprises theLED 3256 aligned along the defined illumination axis with the condenserlens 3264 and the rotatable aperture wheel 3300, as well as theillumination relay lens 3320, each disposed in alignment with an angledmirror 3350, the latter being offset relative to the imaging axis 3132.

In accordance with this embodiment and referring to FIGS. 71(a) and71(b), the mirror support member 3354 can be threadingly fitted into aformed port at the top of the instrument head 3104. A mirror 3350 isattached to a pivotable portion 3360 which can be accessed and enablesadjustment during the time of manufacture. According to one version, themirror 3350 can be adjusted using and adjustment member 3352 that isaccessible through a port formed in the rear of the instrument head3104. The mirror 3350 is further attached to a movable member thatenables additional adjustment of the supported mirror 3350, as needed.The mirror mount assembly described is exemplary. For example, themirror mount assembly 2453 described in the prior embodiment (see FIGS.60(a)-60(f)) can be substituted for this version.

For purposes of this embodiment, the illumination assembly 3101 utilizesa single LED 3256, though the number and color temperature of the LEDcan be suitably varied. According to this embodiment, a magnificationlens 3210 is provided adjacent a window of the necked portion 3107 inorder to permit a caregiver to more easily read the diopter wheelsetting of the herein described ophthalmic device 3100.

FIG. 67 illustrates an illumination ray trace of the herein describedinstrument 3100. According to this embodiment and upon engagementbetween the lower end of the contact pin with the contained battery (notshown) in the instrument handle (not shown), the contained LED 3256 isenergized. The output of the LED 3256 is directed through the centeringring 3251, the condenser lens 3260 and the aperture wheel 3300 along thedefined illumination axis 3310 in which the beam passes through therelay lens 3320 and a polarizer 3340 and is directed against the foldedmirror 3350, whose position is adjusted at the time of manufacturewithin the mirror mount by accessing a threaded adjustment member.

Though the imaging elements of the assembly are also shown in this view,the light does not cross the imaging axis 3132. In addition and also notshown, a portion of the emitted light is directed through a set ofoptical fibers (not shown) through the instrument head 3104 and to thefixation targets positioned at the distal end 3112.

Still referring to FIG. 67, the emitted light from the LED 3256 isreflected from the angled mirror 3350, the latter having an angledsurface that directs the light toward the distal end 3112 of theinstrument head 3104 and more specifically through the objective lens3140. The reflected light passes through the objective lens 3140 and isthen focused onto the eye 3130 of the patient. According to thisembodiment, the focal point of the reflected light is off centerrelative to the front of the eye 3130 of the patient and morespecifically the pupil serving as the image plane wherein the light isthen spread outward onto the back of the eye and more specifically theretina 3137. As shown and described herein, the focused spot is off-linerelative to the optical axis 3132 of the device 3100.

With reference to FIGS. 66 and 68, the imaging of the target (i.e., theretina 3137) is reflected from the back of the eye 3130 to the objectivelens 3140 in which the light is further directed along the definedoptical axis 3132 through the image aperture plate 3188 in which aninverted image is passed. The light is then directed to the relay lens3186, field stop 3197 and through the eyepiece lenses 3180, 3184,respectively, wherein the light is focused onto the eye (not shown) ofthe caregiver as an erect image.

Alternatively and in lieu of the eyepiece, the light can be directedthrough the aperture of a smart device 3106, FIG. 62, such as a smartphone, which is attached to the proximal end 3116 of the device 3100 andaligned in relation to the optical axis 3132. This attachment can bedone in the manner previously described according to FIGS. 6-13(b) orthe alternative techniques described in FIGS. 14-20.

FIG. 73 illustrates an optical layout illustrating scaling forinstrument heads 3404, 3414, such as shown in FIG. 74. Morespecifically, the instrument heads 3404, 3414 can include scaled opticalassemblies maintaining back ends that commonly include relay lenses3440, 3444 and eyepiece lenses 3448, while axially adjusting theposition and dimensionally scaling the objective lens 3424, 3434 andaperture plate 3427, 3437, the latter enabling common interfaces forvarious physical assessment devices.

A benefit of the optics of the illumination assembly is depicted in FIG.75. At the top of the figure is a known ophthalmic illumination assemblyin which the positioning of the condensing lens in which the focusdistance creates a potential issue in which dirt or debris on thecondensing lens can interfere with the resulting examination. The lowerportion of the figure indicates a point focus relative to the front andback surface of the condensing lens that effectively removes this issue,while maintaining a reticle plan focus at infinity.

A general need in the field of diagnostic medicine is that of enhancingversatility and interchangeability between physical assessment devices,such as, for example, otoscopes and ophthalmoscopes. According to oneexample, depicted in FIGS. 76(a) and 76(b), ophthalmoscopes can bereconfigured in order to permit examinations of eye of a patient. Thedepicted ophthalmoscopes 3450, 3470 in these figures are those of Model117 Ophthalmoscope and Model 12800 Pocket Ophthalmoscopes, respectively,each commercially sold by Welch Allyn, Inc of Skaneateles Falls, N.Y. Inaccordance with this exemplary embodiment, each of the instrument heads3454, 3474 are configured to permit otoscopic examinations. Morespecifically, a tip attaching and releasing mechanism is fitted into thedistal end 3456, 3476 of each ophthalmoscope 3450, 3470 to enable thereleasable retention of a disposable speculum tip element 120 at thedistal end as a patient interface, in lieu of an eye cup. For purposesof this conversion, each existing instrument head 3450, 3470 can beconfigured with a distal insertion portion and distal ring membersimilar to that included in the previously described otoscope 100, FIG.2(b).

In use and for purposes of close-up viewing, the existing diopter wheel3462, 3482 of each ophthalmoscope 3450, 3470 can be used to provideaccommodation at a setting of approximately 10-15 diopters, based on thecaregiver's personal vision and the application/use. Each areaccomplished using the rotatable diopter wheel common to the knownophthalmoscopes.

According to a further version, the speculum tip attachment mechanismcan be installed onto the distal end 3456, 3476 of the instrument head3452, 3472 in order to preset the angle of the attached tip element 120relative to the contained light source. Advantageously, this presetpositioning of the attached speculum tip can optimize uniformity andconcentricity of the illuminated light from the contained light sourcein the handle portion of each of the depicted instruments 3450, 3470.

LED Drive Circuitry

Current instrument heads, such as those commercially sold by WelchAllyn, Inc. are wholly halogen lamp based. Electrically, the lampfilament is a piece of wire whose resistance increases with temperature.So, for any given input voltage, the filament heats up which increasesits resistance until the drive circuit reaches a natural equilibrium(heat/light/resistance/current for the given input voltage). When theinput voltage is raised, the lamp filament becomes brighter and when theinput voltage is lowered the lamp filament dims.

Contrasting, all known LED controller ICs in the electronics industryare designed to ignore its input voltage. This is done for a number ofvalid reasons, but the crucial point is that by definition, a systemthat varies voltage as a way of controlling light output iscategorically incompatible with LED technology. Therefore, it is notrecommended to vary/dim LED brightness by changing its input voltage.With the incorporation of both light sources into instrument heads, asolution is needed for driving and dimming both halogen lamps and LEDs.

Accordingly, FIGS. 77-81 describe an exemplary embodiment of circuitryfor controlling LED lighting in an instrument head. The embodimentsdisclosed herein provide numerous enhancements over conventionallighting control circuits. For instance, typical instrument heads areonly compatible with specific instrument handles, because the instrumenthandles provide electrical power to the instrument head, and mustprovide that electrical power in a very specific profile of voltage andcurrent. Thus, instrument heads are not typically usable with differentinstrument handles, requiring a proliferation of instrument heads anddesigns.

For instance, different types of lighting have different electricalproperties. For example, LED light dimming may be achieved by constantvoltage, and thus a constant current, that is pulse-width modulated toreduce the duty time that the LED is on, whereas incandescent lightdimming may be achieved by changing voltages. In addition, traditionalinstrument heads may include alternating current (AC) power sources, andmay only be compatible with lighting that can use AC power, such asincandescent or halogen lighting. Further, different instrument handlesmay be wired with different polarities, requiring the instrument headsto be hardwired to accept the specific polarity. In addition, LEDs andLED drive circuits have strict requirements for polarity. Currentinstrument handles have multiple polarities (+/−, −/+ and a variation ofAC), and therefore the input power must be rectified to a singlepolarity before an LED in the instrument head can be driven.

Advantageously, the circuits disclosed herein are designed to solvethese problems by allowing compatibility between different instrumentheads and instrument handles.

FIG. 77 depicts a block diagram of a circuit 3510 for controlling ordriving LED lighting. The circuit 3510 may be disposed within aninstrument head, such as the instrument head 104 of the otoscope ofFIGS. 1(a)-5 or the instrument head 2004 of the ophthalmoscope of FIG.59(b), which provides power and has buttons for controlling thelighting, including turning on or off, dimming, brightening, etc. Thecircuit 3510 includes a controller 3514, a buck/boost or power circuit3516, and a rectifier circuit 3518. The circuit 3510 may be connected toan instrument handle 3512, and such connection may be through a 2-wireconnection, 3-wire connection, or any other suitable connection havingmultiple wires for voltages and/or signals. Working examples of specificimplementations of the controller 3514, the power circuit 3516, and therectifier circuit 3518 are discussed below with respect to FIGS. 79-81.

FIG. 78 is a flowchart depicting a method 3500 for controlling LEDlighting in an instrument head, by using the circuit 3510 of FIG. 77.With reference to FIGS. 77-78, in one example, at block 3520 aninstrument handle 3512 may be connected to an instrument head, such asthe instrument head 104 of the otoscope of FIGS. 1(a)-5 or theinstrument head 2004 of the ophthalmoscope of FIG. 59(b), where theinstrument head includes the circuit 3510. This connection may bethrough a 2-wire, 3-wire, or other suitable connection. In one example,simple 2-wire connection would only allow the instrument handle 3512 toprovide electrical power (e.g., at specific voltages and currents) tothe circuit 3510. In another example, the instrument head may includeone or more wires with a control signal, such as a serial port, forsending control signals from the instrument handle 3512 to the circuit3510. The signals received by the circuit 3510 from the instrumenthandle 3512 may be an AC voltage or a DC voltage signal having varyinglevels of voltage and/or current.

Based on the signals received by the circuit 3510 from the instrumenthandle 3512, at block 3530 the power profile of the instrument handle3512 may be determined. For instance, the controller 3514 of the circuit3510 may be programmed to sense the voltage, current, polarity, andother signals from the instrument handle 3512, and use this informationto determine what type of instrument handle is in fact connected.

For example, conventional instrument handles may be designed to usevoltage change to control dimming of halogen or other incandescentlamps. In such a case, electrically, the lamp filament is a piece ofwire whose resistance increases with temperature. So, for any giveninput voltage, the filament heats up which increases its resistanceuntil the drive circuit reaches a natural equilibrium(heat/light/resistance/current for the given input voltage). When theinput voltage is raised, the lamp filament becomes brighter and when theinput voltage is lowered the lamp filament dims. Contrasting, all LEDcontroller ICs in the electronics industry are designed to ignore itsinput voltage. This is done for a number of valid reasons, but thecrucial point is that by definition, a system that varies voltage as away of controlling light output is incompatible with LED technology.Therefore, it is not recommended to vary/dim LED brightness by changingits input voltage. With the incorporation of both light sources intoinstrument heads, the present circuit 3510 allows for driving both LEDand incandescent light sources from a single instrument handle 3512.Thus, the controller 3514 could sense the properties described above andmake a determination that the instrument handle connected is of a typetypically used to drive halogen or other incandescent lamps, but thatthis instrument handle now needs to drive LED lighting.

Continuing with method 3500 of FIG. 78, at block 3540, the circuit 3510may be configured for operation at the power profile determined at block3530. This configuration may include configuring the controller 3514and/or the power circuit 3516, as explained in further detail below withrespect to FIGS. 79-81.

Advantageously, configuring the circuit 3510 for operation with theinstrument handle 3512, based upon auto-detection of the handle profile,allows any number of different instrument handles that have beendeployed in the field to be used with the new instrument heads describedherein. Thus, the benefits of the features, such as LED lighting, may berealized even without replacing these previously deployed instrumenthandles. This auto-detection and configuration of instrument heads foruse with instrument handles represent improves the field of medicaldevices, because the technique allows mixing and matching of differenthandles and heads by the clinician or other caregiver, increasingefficiency with which patients may be treated.

Next, at block 3550, the LED lighting of the instrument handle, which isdriven by the power circuit 3516, may be operated and controlled usingthe instrument handle 3512. In order to facilitate operating andcontrolling the LED lighting with different instrument handles 3512 thatmay have very different electrical profiles, the power circuit 3516includes buck-boost voltage conversion that allow variable inputvoltages to be converted into a specified output voltage, where theinput voltages may be above or below the specified output voltages. Thebuck portion of power circuit 3516 decreases a higher input voltage tomeet the requirements of a lower specified output voltage, and the boostportion of power circuit 3516 increases a lower input voltage to meetthe requirements of a higher specified output voltage. Specific detailsof this power circuit 3516 is set forth with respect to FIG. 80. Inaddition, operating and controlling (at block 3550) the LED lightingwith the instrument handle 3512 is also achieved by converting changesin voltage to changes in current, as will be described in more detailwith respect to FIGS. 79-81.

Further, at block 3560 of the method 3500, the controller 3514 candetect an idle state of the instrument handle. Upon detection of an idlestate, the instrument head can be powered off. And, at block 3570, thecontroller 3514 can detect a vibration state of the instrument handle,and can perform a specific action based on that state, such as poweringoff the instrument head.

Another problem identified with portable physical assessment devices isthat of theft of the instrument handles from the charging base. Usingthe controller 3514 to detect state changes, a theft deterrent mechanismthat could be included. For example, an audible alarm could be set offfrom the charging base if the instrument handle is not returned in apredetermined time interval. In addition, an LED indicator can also beprovided on the charging base when the alarm feature is enabled.

An electrical circuit design can provide a controller that generates anaudible alarm if the instrument handle is not returned to the chargingbase, such as base 1800, FIG. 52, in a defined amount of time.

In another embodiment, an auto-off feature will turn off the instrumentafter a predetermined time period of inactivity. In such an example, thecontroller is programmed with a timer. If a motion sensor subsystem thatis connected to the controller fails to report any motion during thetime period, as counted by the timer, the system will turn off theinstrument.

FIG. 79 is a circuit diagram of the controller 3514 and affiliatedcircuitry. In the embodiment of FIG. 79 the controller 3514 may be amodel CY8C4025LQI-S401 microcontroller available from CypressSemiconductor Corporation, of San Jose, Calif., USA. In otherembodiments, discrete logic elements may be employed instead of amicrocontroller.

As shown in FIG. 79, the controller 3514 is connected to the inputvoltage that has passed through the rectifier of FIG. 81. The rectifieris needed because the LEDs may be powered by direct current rather thanalternating current. The rectified voltage then is input into thecontroller 3514, which then outputs a pulse width modulation signalLED_PWM. The LED_PWM signal is input into the buck/boost or powercircuit 3516, as depicted in FIG. 81. Any of a number of PWM algorithmsmay be used with the circuit. For instance, in traditional voltage baseddimming, a voltage vs. brightness curve may be described that relates agiven voltage to a given brightness. A linear relation would mean thatif the voltage is reduced by 50% from a nominal high voltage, thebrightness would reduce by 50%. In order to translate this into dimmingan LED, a PWM signal that is on for 50% of the time would power an LEDhalf the time and thus achieve 50% brightness.

In other embodiments, a non-linear relationship between the voltage anbrightness may be observed. In one example, a calibration of a legacyhandle and legacy incandescent head can be carried out, so that thelegacy handle can later be used with a new head of the presentdisclosure. For example, the calibration process could use the legacyhandle connected to the legacy incandescent head, and the legacyhandle's voltage may be varied from maximum to minimum while measuringthe brightness percentage as a function of voltage. The resultingcalibration data set relates voltage to expected brightness percentagefor the legacy handle. This calibration curve can be loaded into thecontroller on an instrument head of the present disclosure so that thebrightness control of the legacy handle will have the same effectiveresult when using the new instrument head.

The controller would achieve this by detecting the input voltage fromthe handle, and using a lookup table containing the calibration data setto find the appropriate desired brightness percentage. Then, instead ofapplying the input voltage to the LED, the input voltage would bebuck/boost converted to yield a constant LED current. The brightnesswould be controlled by a PWM signal that turned on and off the LED suchthat the LED was on for the desired brightness percentage of the time,and off the rest of the time. In such a manner, numerous differentlegacy handles with different voltages can be profiled to findcalibration data for use in the instrument head described herein.

In an embodiment, the controller 3514 receives the input voltage VINfrom the instrument handle and determines its polarity. Depending on thepolarity of the voltage VIN received from the instrument handle, andpotentially other indicia such as power on signals, initial voltage,etc., the controller can determine the power profile for that specificinstrument handle, e.g., by using a lookup table that lists all theknown instrument handles and their known polarities, initial voltages,power on signals, etc. In such a case, the controller can determine whattype of instrument handle has been attached, and then can access thevoltage calibration curve of the instrument handle, which relates thevoltage to the output illumination level of the LED as explained above.The LED_PWM signal from the controller may the appropriately drive a PWMsignal of the correct duty cycle (e.g., percentage on to off) to achievethe brightness of the LED that corresponds to the brightness that anincandescent instrument head would output if the same instrument headwere connected to it and directly driven using the voltages. In such amanner, the input voltages changes have been converted to PWM signals ofspecific duty cycles of a constant current that can be used to power anddim an LED. In another example, specific pins on the instrument handlemay carry identification or handshake data that tells the instrumenthead which handle has been connected, allowing the controller to lookupa pre-loaded power profile for that handle.

In an embodiment, the controller 3514 may also determinevibration/motion or idle states of the instrument head and/or handle,and perform appropriate actions as described with respect to method 3500above. In one example, idle states can be determined by a lack of motionsensor indicated activity during a predetermined time period, and theaction can be to shut off the instrument. In another example, motion ofthe instrument can be detected by the motion sensor, and an idle timercan be reset, or other subsystems may be turned on.

FIG. 80 is a circuit diagram of the buck/boost or power circuit 3516. Inthe example of FIG. 80, the power circuit 3516 is based on a TPS63036Buck/Boost converter U5 with support for receiving the LED_PWM signalsfrom the controller as described above. The TPS63036 is available fromTexas Instruments Inc., Dallas, Tex., USA. In the circuit diagram ofFIG. 80, we see that the input voltage is fed into the converter U5,which is also controlled using the EN and PWM_LED signal from thecontroller 3514, in order to apply the PWM profile to dim the LEDlighting as noted above with respect to FIG. 79.

In operation, the buck/boost or power circuit 3516 may receive the inputvoltage VIN and provide an output voltage VOUT that generates a fixed orconstant current for powering the LED lights. The output voltage VOUTmay be tuned by appropriately setting resistors R1 and R2, in thespecific example using a TPS63036 converter. Once set up, the buck/boostor power circuit 3516 would output the fixed or constant current forpowering the LEDS, and the PWM_LED wire from the controller 3514 wouldbe used to provide the PWM signal with the appropriate duty cycle forachieving a specific brightness. In other examples, the buck and boostportions of the circuit may be implemented separately using discretecomponents instead of a single buck/boost converter. In such a case, thecircuit would boost a VIN that was less than VOUT through a boostingsub-circuit, and decrease or buck a VIN that was greater than VOUTthrough a buck sub-circuit.

FIG. 81 is a circuit diagram of the FET full-wave bridge circuit 3518.Rectification to a single polarity is typically done with a diode FullWave Bridge (FWB). Diode FWB's typically lose between 1V and 1.4V in therectification process. This is a considerable proportion of the LEDvoltage, which is typically 2.7V. That ratio approximates the loss ofenergy from the battery never to produce light. In order to minimizelosses associated with a diode full-wave-bridge, a FET full-wave-bridgeis introduced, as shown in FIG. 81. The FET FWB design only loses about50 mV, depending upon the current and FETs selected. The energy not lostmeans energy available to produce light and increasing overall batterylife of the device.

The FET FWB circuit design is made up of two NFETs, two PFETs, and thenecessary capacitors. The FET full-wave-bridge has considerable ESDprotection, mostly realized in capacitors across the gate-source foreach FET.

In accordance with another embodiment and with reference to FIG. 82, aninstrument head for a physical assessment device is configured with abuck convertor head design, which is an LED controller circuit designthat will drive an LED effectively and without risk of instability (LEDFlicker) with a PWM (Bang-Bang) power source.

For the power source, a traditional RC hysteretic oscillator (nicknamedbang-bang in the electronics world) will be used. This power source willdrive both a halogen lamp head and the LED instrument head having thebuck converter. For the buck converter LED driver head, and while theinput voltage is sufficient, there is controlled brightness. For outputvoltage varying power sources (as the drive voltage lowers (dimming)),the buck converter eventually runs out of headroom and the LED is drivendirectly by the driving voltage (in series with the parasiticresistances of the controller and the mechanical system). This occurswhen V_(in) approaches the LED's VF plus the controller's sense voltageplus the parasitic IR losses. For a PWM power source, as long as theoutput voltage is greater than the LED's VF, the bang-bang dimming willdim the LED effectively and without instability (flicker). For purposesof this specific embodiment, the circuit is the PAM2804 IC LED driverapplied as the manufacturer recommends. The PAM2804 is a suitableexample of an LED Driver IC since it will run down to the appropriatevoltage of 2.5V. This is an anomaly because no high brightness LED has aforward voltage of 2.5V. The 2.5V capable DC-DC converter IC,PAM2312-ADJ, can be repurposed for LED drive by lowering its referencevoltage from 0.6V to 0.1V.

An alternative drive circuit is shown in FIG. 83 in which R25, R26 andR27 are additionally provided to enable fine tuning in order to adjustthe LED effective forward voltage. This capability enables a number ofLEDs to operate in a representative manner across instrument heads andhandles.

LED's and LED drive circuits have strict requirements for polarity.Current instrument handles have multiple polarities (+/−, −/+ and avariation of AC), and therefore the input power must be rectified to asingle polarity before an LED in the instrument head can be driven.

Rectification to a single polarity is typically done with a diode FullWave Bridge (FWB). Diode FWB's typically lose between 1V and 1.4V in therectification process. This is a considerable proportion of the LEDvoltage, which is typically 2.7V. That ratio approximates the loss ofenergy from the battery never to produce light. In order to minimizelosses associated with a diode full-wave-bridge, a FET full-wave-bridgeis introduced, as shown in FIG. 82. The FET FWB design only loses about50 mV, depending upon the current and FETs selected. The energy not lostmeans energy available to produce light and increasing overall batterylife of the device.

The FET FWB circuit design is made up of two NFETs, two PFETs, and thenecessary capacitors. The FET full-wave-bridge has considerable ESDprotection, mostly realized in capacitors across the gate-source foreach FET.

While a 2-wire voltage varying input is the standard method foradjusting brightness for a halogen or incandescent lamp, it'sproblematic for LED circuits as has happened in the commercial andresidential lighting industry. The most significant issue is loopstability going unstable, causing LED's to blink. This can be a seriousproblem in physical assessment devices such as ophthalmoscopes,otoscopes, etc. Industry LED circuits rely upon pulse width modulationfor dimming LEDs. In order to drive both an LED and halogen based lampfrom a single voltage varying power source an electrical solution mustbe designed.

The herein described electrical circuit design shown in FIGS. 83(a),83(b) will drive both an LED and halogen based lamp from a singlevarying power source and maintain loop stability so that there is norisk of blinking LEDs.

This electrical circuit design works when first energized, the output ofthe comparator is low, turning on the PFET. Assuming the LED voltage toapproximate a constant, the voltage across the Power Inductor willapproximate a constant. As such, current will rise at a linear rate.This causes a positive slope voltage ramp across the sense resistor. Forpurposes of this circuit, this sense voltage is “faked” low at thepositive input of the comparator by the voltage divider (ratio HystRes/(hyst Res×FeedBack Res). When this comparator positive input voltagereaches VREF, the comparator output goes high, turning off the PFET.This is called the “Upper Threshold” of the hysteresis circuit. Thisoutput swing instantaneously reverses the voltage divider, faking thesense current high instead of low at the positive input to thecomparator. As such, the current must go to the Lower Threshold of ahysteresis circuit before it crosses+VREF before the output will againgo low. While the PFET is turned off (comparator output high), currentcontinues to flow through the inductor, through the catch diode, causinga negative slope across the sense resistor.

When the current reaches the lower threshold, the output goes low,turning on the FET and the cycle continues. Since the sense voltage rampis nearly linear both up and down, the average current will be the+VREF/SENSE RESISTOR. In other words, given a triangle wave, there willbe half the area above and below its average. The circuit is regulatedand controlled. The only drawback is high ripple current, but thisdoesn't matter for a LED, especially since practical frequencies are farabove what the human eye can detect. More so, increasing the outputcapacitor (C17) of the hysteretic current source will reduce the ripplecurrent and make the slopes more linear. Of more importance though, isthat there is no high gain closed loop most often used in power supplycontrol circuits, including LED drivers. Since the oscillation is nomore than an inductor being charged and discharged while banging intotwo predictable thresholds, the instability of the oscillator cycleeliminates the chance of subharmonic oscillations that traditionalcontrollers are prone to. In other words, the connected LEDs will not beprone to blinking.

This described circuit is stable. This circuit also does not dim withinput voltage so no advantage is otherwise over traditional LED drivercircuits. However, and if the reference voltage is varied as a functionof input voltage (something that cannot be done with traditional powersupply—including LED controllers—control loops without riskinginstability), the LED current will vary as a function of input voltage.Unlike high-gain control loops which vary many of their stabilityparameters with input voltage and reference voltage changes, thehysteretic controller continues to bang between the upper and lowerthresholds and the average is the reference voltage. The addition of avoltage divider to create+VREF and the LED voltage will varyproportionally to +VIN.

As previously discussed, another problem identified with portablephysical assessment devices that require base charging is that of theftof the instrument handles from the charging base. Another object of theherein described invention is to provide a theft deterrent mechanismthat would be included in the charging base.

Such theft detection could include an audible alarm from the chargingbase if the instrument handle is not returned in a predetermined timeinterval. In addition, an LED indicator can also be provided on thecharging base when the alarm feature is enabled.

An electrical circuit design can provide a controller that generates anaudible alarm if the instrument handle is not returned to the chargingbase, such as base 1800, FIG. 52, in a defined amount of time. Accordingto one version, there are four (4) pogo pins provided in the chargingbase; a positive contact, two negative contacts, and one contact forinstrument handle detection. This handle detection contact would be whattriggers the time period once the instrument handle is removed and stopthe timer once the handle is placed back into the charging base. Inaddition, an LED indicator on the charging base can be illuminated toalert individuals that the theft alarm is enabled. This LED indicatorwould flash/blink when the audible alarm is sounded. A switch can beprovided on the bottom or otherwise upon the charging base toenable/disable the alarm feature. This switch could be recessed in thehousing of the charging base and be made only accessible by aspecialized tool or other access feature, such as small piece of metal(e.g., a paper clip). There may also be some other type of switch to setthe defined time for the alarm to enable once the handle is removed.

Capturing Images with Minimal Defects and/or Artifacts

Conventional instrument heads are either wholly halogen lamp based ormake use of LED lights that are dimmed using pulse width modulation(PWM) in which the LED is rapidly switched on and off. The speed withwhich the LEDs are switched on and off is so rapid that the human eyeperceives constant illumination at a lower brightness level, and doesnot sense that the LED is ever fully turned off. By contrast, imagingequipment, including stand-alone cameras and smart phones, operate at aspeed much faster than the human eye. If imaging equipment is used tocapture images through an instrument which uses PWM dimmed LED lighting,under certain circumstances image defects and artifacts appear when theimaging equipment attempts to capture an image during an off-cycle ofthe PWM dimmed LED lighting. These defects and artifacts can appearunder various circumstances, but generally are caused by the capturedevice trying to capture an image with insufficient illumination.

Indeed, modern imaging equipment, such as that used in smart phones, canuse a digital technique that serially generates an image from top tobottom or left to right. During such a scan, which takes a specificperiod of time, if the PWM LED lighting cycles from on to off (one ormore times) certain image areas will be captured as completely dark. Theresulting image will thus include certain dark bands, leading to astriped light/dark pattern in the image which will obscure details ofthe anatomy being examined. For instance, a retinal scan will includestriped patterns, and the resulting images will be useless fordiagnosis.

For example, FIG. 87 depicts PWM dimming of a drive circuit driving anLED light with a waveform 8700. As depicted in FIG. 87, waveform 8700oscillates between on and off at with a frequency of 544.7 Hertz. Duringthe on-cycle, the circuit delivers current to the LED light. Conversely,during the off-cycle, no current is delivered to the LED light. Such awaveform 8700 leads to the illumination of the LED light being dimmed.

However, FIGS. 87A and 87B depict images that include artifacts when theillumination is dimmed using PWM dimming. FIG. 88A depicts an image8800A of a medical target. As seen in FIG. 88A, dark bands 8805 runvertically through the image, and are artifacts of PWM dimming thatobscure the image 8800A. Additionally, the illumination can createinterference as a result of reflections and interaction with the cellphone image capture software as seen in FIG. 88B, which is an image8800B of a medical target, such as a retina. Image 8800B includesartifacts 8810 when dimmed using the PWM dimming of FIG. 87. Theseartifacts appear as dark bands which obscure the medical target and insome cases can cause the image capture device to be unable to focus andcapture the images. Without wishing to be limited or bound by theory,Applicant believes that these artifacts are caused by the serialdigitization of the image by the capture devices, such that subsequentrows of the image are being digitized during the off-cycle of the PWMwaveform 8700 and the image processing capability of the image capturedevice.

FIG. 89 depicts one example of a drive circuit 8900 for capturing imagesof medical targets free of artifacts in accordance with an embodiment.As may be seen in FIG. 91, the substantially triangle waveform 9100slowly declines towards zero, instead of sharply reaching zero like thePWM waveform 8700 of FIG. 87. This allows the LED light to have someillumination of the medical target throughout the duty cycle, ensuringthat when the camera captures an image, there is enough illumination toavoid artifacts.

Circuit 8900 includes: a comparator U1, e.g., model MCP6541UT-E/OTavailable from Microchip Technology of Chandler, Ariz., USA; a P-channelMOSFET Q1, e.g., model SI2301BDS-T1 available from Siliconix, San Jose,Calif., USA; and the following discrete components: resistors R1 (150kilo-ohm), R2 (1 mega-ohm), R3 (33.2 kilo-ohm), R4 (54.9 kilo-ohm), R5(100 ohm), R6 (1.8 kilo-ohm), RP1 (100 kilo-ohm), and capacitor C2 (470pico-farad). In circuit 8900, capacitor C2 and resistor R4 (which impactthe time constant), gate driver resistor R5 and U1 are selected so thatthe drive circuit 8900 outputs a pulse width modulation (PWM) with afrequency selected to illuminate an LED such that the frequency issufficiently fast such that the output to the LED never fully turns offand ensures that the image is illuminated with no more than somemodulation during the time it takes for a smart phone camera to capturean image.

For instance, the drive circuit 8900 may be tuned with selectedcapacitor C2 and resistor R5 to output a PWM waveform 8900 that operatesat a frequency with a period two, three or more times the time constantof the attached circuit or device to be illuminated, ensuring sufficientillumination to avoid defects.

FIG. 90 depicts another example of a drive circuit 9000 which produces aconstant regulated current to an LED. The digital parameters of drivecircuit 9000 are converted to analog. Circuit 9000 includes a buck-boostdriver U5, e.g., model TPS6303X available from Texas Instruments,Dallas, Tex., USA; low-dropout regulator U7; MOSFET Q4, e.g., modelSI1022 available from Sliconix; resistors R1 (4.99 kilo-ohm), R2 (15kilo-ohm), R28 (2 ohm), R36 (1 kilo-ohm), R37 (10 kilo-ohm), R39 (2ohm), R42 (24.3 kilo-ohm), R49 (100 kilo-ohm), R50 (10 kilo-ohm);capacitors C11 (100 nano farad), C12 (10 micro farad), C15 (4.7 microfarad), C16 (10 micro farad), C26 (10 micro farad), C30 (100 nanofarad); and inductor L1 (1.5 micro henry). For instance, the drivecircuit 9000 may be tuned by selecting resistor R37, capacitor C26, anddriver U5, in order to change the PWM input to a generally analogfeedback signal to U5. U5 then regulates the output to the LED as aconstant current.

FIG. 92 depicts an example of capturing an image 9200 of medical targetfree of artifacts using either the drive circuit 8900 (FIG. 89) or thedrive circuit 9000 (FIG. 90). As may be seen when comparing FIG. 92 withFIG. 88, the artifacts 8810 have been eliminated so that all of thedetails, such as blood vessels, of the medical target are visible. Ofcourse, in other examples, the medical target may be any of thedifferent types of targets described herein.

By way of summary, FIGS. 87-92 describe, in one embodiment, a physicalassessment device. For instance, the physical assessment device includesan instrument head, an optical assembly and an adapter interface member.The instrument head has a distal end, an opposing proximal end and aninterior. The instrument head includes an illumination assemblyincluding at least one LED and a drive circuit for powering the at leastone LED with a pulse width modulation (PWM) current to achieve avariable brightness of the at least one LED. The optical assembly isdisposed within the instrument head and includes a plurality of opticalcomponents disposed along an optical axis. The adapter interface memberis disposed at the proximal end of the instrument head, and enables animage capture device to be attached to the instrument head and alignedwith the optical axis. The image capture device is configured to captureimages of medical targets when illuminated by the at least one LED withthe variable brightness. The drive circuit is coordinated with the imagecapture device to ensure that the medical targets are at least partiallyilluminated during the capturing of the images notwithstanding thevariable brightness of the at least one LED being achieved using the PWMcurrent. In one example, the drive circuit is coordinated with the imagecapture device to ensure that the medical targets are at least partiallyilluminated during the capturing of the images by selecting a frequencyof a duty cycle of the drive circuit to include at least two on-cyclesof the PWM current to overlap with an image scanning period of the imagecapture device. In another example, the drive circuit is coordinatedwith the image capture device to ensure that the medical targets are atleast partially illuminated during the capturing of the images byselecting the drive circuit to output a substantially triangle wavecurrent with a minimum current value greater than zero. In anotherexample, the PWM current is selected such that the images of the medicaltargets captured by the image capture device are free of defects orartifacts notwithstanding the variable brightness of the at least oneLED. In another example, the variable brightness of the at least one LEDis selected to provide sufficient illumination for the image capturedevice to autofocus the medical targets. In another example, the imagecapture device captures the images by serially generating each of theimages from top to bottom or from left to right.

Additional variations and modifications of the inventive concepts whichare described herein will be readily apparent based on the abovedescription and further in accordance with the following claims.

1. A physical assessment device comprising: an instrument head having adistal end, an opposing proximal end and an interior, the instrumenthead comprising an illumination assembly including at least one LED anda drive circuit for powering the at least one LED with a pulse widthmodulation (PWM) current to achieve a variable brightness of the atleast one LED; an optical assembly disposed within the instrument headincluding a plurality of optical components disposed along an opticalaxis; and an adapter interface member disposed at the proximal end ofthe instrument head, the adapter interface member enabling an imagecapture device to be attached to the instrument head and aligned withthe optical axis, the image capture device being configured to captureimages of medical targets when illuminated by the at least one LED withthe variable brightness, wherein the drive circuit is coordinated withthe image capture device to ensure that the medical targets are at leastpartially illuminated during the capturing of the images notwithstandingthe variable brightness of the at least one LED being achieved using thePWM current.
 2. The physical assessment device of claim 1, wherein PWMcurrent is selected such that the images of the medical targets capturedby the image capture device are free of defects or artifactsnotwithstanding the variable brightness of the at least one LED.
 3. Thephysical assessment device of claim 1, wherein the variable brightnessof the at least one LED is selected to provide sufficient illuminationfor the image capture device to autofocus the medical targets.
 4. Thephysical assessment device of claim 1, wherein the image capture devicecaptures the images by serially generating each of the images from topto bottom or from left to right.
 5. The physical assessment device ofclaim 1, wherein the drive circuit is coordinated with the image capturedevice to ensure that the medical targets are at least partiallyilluminated during the capturing of the images by selecting a frequencyof a duty cycle of the drive circuit to comprise at least two on-cyclesof the PWM current to overlap with an image scanning period of the imagecapture device.
 6. The physical assessment device of claim 5, whereinthe PWM current is selected such that the images of the medical targetscaptured by the image capture device are free of defects or artifactsnotwithstanding the variable brightness of the at least one LED.
 7. Thephysical assessment device of claim 5, wherein the variable brightnessof the at least one LED is selected to provide sufficient illuminationfor the image capture device to autofocus the medical targets.
 8. Thephysical assessment device of claim 5, wherein the image capture devicecaptures the images by serially generating each of the images from topto bottom or from left to right.
 9. The physical assessment device ofclaim 1, wherein the drive circuit is coordinated with the image capturedevice to ensure that the medical targets are at least partiallyilluminated during the capturing of the images by selecting the drivecircuit to output a substantially triangle wave current with a minimumcurrent value greater than zero.
 10. The physical assessment device ofclaim 9, wherein the PWM current is selected such that the images of themedical targets captured by the image capture device are free of defectsor artifacts notwithstanding the variable brightness of the at least oneLED.
 11. The physical assessment device of claim 9, wherein the variablebrightness of the at least one LED is selected to provide sufficientillumination for the image capture device to autofocus the medicaltargets.
 12. The physical assessment device of claim 9, wherein theimage capture device captures the images by serially generating each ofthe images from top to bottom or from left to right.